The invention relates to an optical resonator, laser apparatus and a method of generating a laser beam inside an optical resonator. The optical resonator (100) includes an optical cavity (102) and an optical element (104.1, 104.2) at either end thereof, operable to sustain a light beam (108) therein, characterized in that each optical element (104.1, 104.2) is a phase-only optical element operable to alter a mode of the beam (108) as it propagates along the length of the optical resonator (100), such that in use the beam (108) at one end of the optical resonator (100) has a Gaussian profile while the beam (108) at the other end of the optical resonator (100) has a non-Gaussian profile.

An intra-cavity frequency doubled OPS-laser includes a laser-resonator terminated by a plane mirror and a mirror-structure of an OPS-chip. The resonator is folded by three fold-mirrors. The fold-mirrors are supported on a vibration-isolation plate supported by isolation posts above a base-plate. The plane mirror and the mirror-structure of the OPS-chip are mounted back to back on opposite parallel surfaces of a mounting block. The mounting-block is supported on the base-plate and extends through an aperture in the vibration-isolation plate. Movement of the vibration-isolation plate with respect to the base-plate does not change the resonator length.

A method for quasi-synchronous tuning of wavelength or frequency of grating external-cavity semiconductor laser and a corresponding semiconductor laser are provided. A grating or mirror is rotated around a quasi-synchronous tuning point (Pq) as rotation center, so as to achieve the frequency selections by grating and resonance cavity in quasi-synchronous tuning, wherein the angle of the line between the quasi-synchronous tuning point (Pq) and a conventional synchronous tuning point (P0) with respect to the direction of light incident on the grating is determined according to the angle difference between the incidence angle and diffraction angle of light on the grating. According to present invention, approximately synchronous tuning of laser is achieved with a simple and flexible design.

A method for fabricating a group-III nitride semiconductor laser device stably supplies laser cavity mirrors having a low lasing threshold current through the use of a semi-polar plane. A blade 5g is forced down through a first region ER1 to keep the first region ER1 squeezed between a support member H2 and a movable member H1 together with a part of a protective sheet TF in contact with the first region ER1 while the tension generated in the area of the protective sheet TF in contact with the first region ER1 with the movable member H1 increases until the semi-polar principal surface SF at an end face EG1 of the first region ER1 tilts by a deflection angle THETA from the semi-polar principal surface SF of a second region ER2, and a force is thereby generated in the first region ER1 in a direction opposite to the direction of travel of the blade 5g toward the first region ER1. For example, an angle ALPHA is within the range of 71 degrees to 79 degrees, and the deflection angle THETA is within the range of 11 to 19.

Tensile strained germanium is provided that can be sufficiently strained to provide a nearly direct band gap material or a direct band gap material. Compressively stressed or tensile stressed stressor materials in contact with germanium regions induce uniaxial or biaxial tensile strain in the germanium regions. Stressor materials may include silicon nitride or silicon germanium. The resulting strained germanium structure can be used to emit or detect photons including, for example, generating photons within a resonant cavity to provide a laser.

A semiconductor laser includes a semiconductor nanowire of a first conductivity type provided over a substrate, a light emitting layer provided around the semiconductor nanowire and insulated at an upper end and a lower end thereof, a cladding layer of a second conductivity type different from the first conductivity type, the cladding layer being provided at an outer periphery of the light emitting layer, a first electrode electrically coupled to an end portion of the semiconductor nanowire, a second electrode electrically coupled to an outer periphery of the cladding layer, a first reflection mirror provided at a one-end portion side of the semiconductor nanowire, and a second reflection mirror provided at the other end portion side of the semiconductor nanowire.

A fiber coupled semiconductor device and a method of manufacturing of such a device are disclosed. The method provides an improved stability of optical coupling during assembly of the device, whereby a higher optical power levels and higher overall efficiency of the fiber coupled device can be achieved. The improvement is achieved by attaching the optical fiber to a vertical mounting surface of a fiber mount. The platform holding the semiconductor chip and the optical fiber can be mounted onto a spacer mounted on a base. The spacer has an area smaller than the area of the platform, for mechanical decoupling of thermally induced deformation of the base from a deformation of the platform of the semiconductor device. Optionally, attaching the fiber mount to a submount of the semiconductor chip further improves thermal stability of the packaged device.

A method for providing a feedback circuit for a three dimensional projector. First and second input devices and a sensor for determining the rotational speed of the second input device are provided. A control device for controlling the rotational speed of the second input device and a phase locked loop (PLL) are provided. A phase reference signal is created based on the signal rate of the first input device. A phase signal is created based on the rotational speed of the second input device. The PLL compares the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized. A signal is sent to the control device for the second input device to change the rotational speed of the second input device in response to determining that the first input device and the second input device are not synchronized.

A method to tune an emission wavelength of a laser diode (LD) finely is disclosed. The method first controls a temperature of the etalon filter in T1 or T2, where the transmittance of the etalon filter becomes 40 to 50%, assuming a height between the peak and the bottom of the periodic transmittance to be 100%, at the grid wavelength λ1 or λ2, respectively. Then, the temperature of the LD is adjusted such that the intensity of light emitted from the LD and transmitted through the etalon filter becomes 40 to 50%.

Novel methods and systems for miniaturized lasers are described. A photonic crystal is bonded to a silicon-on-insulator wafer. The photonic crystal includes air-holes and can include a waveguide which couples the laser output to a silicon waveguide.

A device including one or more layers with lateral regions configured to facilitate the transmission of radiation through the layer and lateral regions configured to facilitate current flow through the layer is provided. The layer can comprise a short period superlattice, which includes barriers alternating with wells. In this case, the barriers can include both transparent regions, which are configured to reduce an amount of radiation that is absorbed in the layer, and higher conductive regions, which are configured to keep the voltage drop across the layer within a desired range.

Disclosed is an ASE-free continuously tunable external resonator laser in which reduction in tuning range and decrease in output are suppressed. The external resonator laser comprises: a fixed support body which has a half mirror that partially reflects incident light and partially transmits incident light fixed therein; and a rotatory support body which is rotatably supported by the fixed support body by way of a shaft, and which has a laser chip that emits light, a collimator lens that collimates light emitted from the laser chip, and a diffraction grating that diffracts light emitted from the laser chip, fixed therein.

An adhesive applicator is disclosed for the application of a hot melt adhesive to the spine of a book block so as to adhesively bind the book block to its respective cover so as to form a perfect bound book. The applicator has a heated head in which a small quantity of a hot melt adhesive sufficient to bind at least one book block to its cover is quickly heated to a temperature such that it may be applied to the spine. The head is brought into operative engagement with the spine and is moved with respect to the spine so that the melted adhesive forced (dispensed) out of the head onto the spine. This applicator is particularly well suited for use with print on demand book printing and binding apparatus. A method of applying the adhesive to the spine of a book block is also disclosed.

Methods for creating customized children's storybooks with fingerprint art using fingerprint-ready templates stored in association with a software application on a desktop computer, a tablet computer, or a smart phone. The methods include the use of preconfigured templates and prompted discussions that elicit responses from the child to create text for the storybook. The text may be generated by speech recognition software processing digital audio recordings of the child's responses. A digital image of the child's fingerprint is acquired and the fingerprint image and/or the storybook scenes are scaled to fit each other. Fingerprint-ready image templates are used to facilitate the creation of fingerprint art. A completed page image is formed by digitally inserting a fingerprint into the fingerprint-shaped area, and if desired, coloring the image or drawing a scene around the image. When the scenes are completed the software application compiles the book pages and prints the same.

A windshield wiper arm bracket includes a pair of side walls. Each of said side walls include at least one centrally located pin arm receiving hole formed therein. The bracket also includes a post attaching the pair of side walls together. The post is for receiving a pin arm adaptor thereon. The bracket also includes an attachment arm formed on a bottom of each of the pair of side walls. The attachment arms are for connecting the bracket to a windshield wiper assembly. An adaptor for a windshield wiper arm bracket includes a top portion and a web portion. The web portion includes a central aperture formed therein. The central aperture includes a first portion for receiving a post of the windshield wiper arm bracket and a second aperture for receiving a pin arm of a windshield wiper arm.

A manufacturing method and device for supporting conductors. Using a non-metallic insulating material extending beyond one or both parallel legs of a staple the thumb and forefinger may grip this extension while the staple is being driven into a supporting structure. This finger grip allows for a small, insulated staple to be held with increased safety to thumb and forefinger during penetration of staple into support.

A generator stator core through-bolt tensioning device that automatically tightens the nut on the through-bolts that hold together and compress laminate plates of the stator core in a high voltage generator. A controller receives a signal from a measuring device, such as a fiber Bragg grating that measures the strain on the bolt, and based on that signal determines whether the nut needs to be tightened. If the controller determines that tightening is necessary, it will cause the tensioning device to automatically tighten the nut while the generator is in service, and use the measuring device to provide feedback of the tensioning of the through-bolt to know when to stop the device from tightening the nut.

A threaded connector for securing a panel member to a structure and for adjusting the position of the panel member relative to the structure. The connector comprises an elongate one-piece stud, a first spacer, a threaded nut, a second spacer and a turning formation. The connector permits the panel member to be mounted on the stud and the stud to be rotated to adjust the position of the panel member relative to the structure.

A method and system for synchronizing the output signal phase of a plurality of frequency divider circuits in a local-oscillator (LO) or clock signal path is disclosed. The LO path includes a plurality of frequency divider circuits and a LO buffer for receiving a LO signal coupled to the plurality of frequency divider circuits. The method and system comprise adding offset voltage and setting predetermined state to each of the frequency divider circuits; and enabling the frequency divider circuits. The method and system includes enabling the LO buffer to provide the LO signal to the frequency divider circuits after they have been enabled. When the LO signal drives each of the frequency divider circuits, each of the frequency divider circuits starts an operation. Finally the method and system comprise removing the offset voltage from each of the frequency divider circuits to allow them to effectively drive other circuits.

A semiconductor device that includes transistors having the same polarity consumes less power and can prevent a decrease in amplitude of a potential output. The semiconductor device includes a first wiring having a first potential, a second wiring having a second potential, a third wiring having a third potential, a first transistor and a second transistor having the same polarity, and a plurality of third transistors for selecting supply of the first potential to gates of the first transistor and the second transistor or supply of the third potential to the gates of the first transistor and the second transistor and for selecting whether to supply one potential to drain terminals of the first transistor and the second transistor. A source terminal of the first transistor is connected to the second wiring, and a source terminal of the second transistor is connected to the third wiring.

An output thin film transistor threshold voltage offset compensation circuit, a GOA circuit, and a display. The circuit includes: a first capacitor, comprising a first electrode and a second electrode, the first electrode being connected to the gate of an output thin film transistor and receiving a charge signal, the second electrode being connected to the drain of the output thin film transistor, the first capacitor being used for, under the action of the charge signal, making the first electrode and the second electrode have a same voltage, so that a voltage difference between the drain and the source of the output thin film transistor is equal to a threshold voltage thereof; a first switch unit, connected to the drain and the source of the output thin film transistor, and opening under the action of a first clock signal, so that a voltage difference between the gate and the source of the output thin film transistor is equal to the threshold voltage thereof.

A semiconductor device which shifts a low-level signal is provided. In an example, a first transistor including a first terminal electrically connected to a first wiring and a second terminal electrically connected to a second wiring, a second transistor including a first terminal electrically connected to a third wiring and a second terminal electrically connected to the second wiring, a third transistor including a first terminal electrically connected to a fourth wiring and a second terminal electrically connected to a gate of the second transistor, a fourth transistor including a first terminal electrically connected to a fifth wiring, a second terminal electrically connected to a gate of the third transistor, and a gate electrically connected to a sixth wiring, and a first switch including a first terminal electrically connected to the third wiring and a second terminal electrically connected to a gate of the first transistor are included.

A trailer for transporting an agricultural harvesting head includes a pair of saddles for supporting the head. The saddles are adjustably mounted on the trailer frame and are simultaneously moved together by an actuator operated by a remote control. The saddles are connected by telescoping rod sections so that the spacing between the saddles is adjustable.

There is provided a transport vehicle for transporting wind power installation rotor blades and/or pylon segments. The transport vehicle has a transport support structure having a main frame, a receiving frame fixedly connected to the main frame at a first angle, and a rotary displacement unit which is fixed with one end to the receiving frame and which at its second end has a blade adaptor for receiving a rotor blade or a pylon segment. The main frame spans a main plane. The rotary displacement unit has at least one first rotary mounting, wherein there is provided a second angle between the second rotary plane of the second rotary mounting.

A transportation and storage system for a wind turbine rotor blade comprises a tip end frame assembly comprising a tip end receptacle and a tip end frame. The tip end receptacle comprises an upwardly open tip end-receiving space for receiving a portion of the tip end of the blade and having a supporting surface for supporting the blade, a lower surface allowing the tip end receptacle to rest upright on a substantially horizontal surface, such as the ground, and releasable retaining means for releasably retaining the tip end of the blade in the receiving space of the tip end receptacle. The tip end frame comprises an upwardly open receptacle-receiving space for receiving the receptacle and provided with positioning means for positioning the receptacle in the tip end frame. A base part defines a bottom surface allowing the tip end frame to rest upright on the ground.

An adjustable cargo storage press for organizing and securing cargo items stored in a cargo storage area of an automobile. The adjustable cargo storage press is disposed within or integrated with a cargo area of an automotive vehicle such as a trunk, bed or bed liner of a car, truck, or sport utility vehicle. The press prevents movement of cargo items and potential damage to the cargo items during transport. The press also maintains the position of the cargo items for easy removal from the cargo storage area. The press includes one or more hinged walls that lock in a vertical position and move towards each other along guide tracks. The one or more hinged walls compress the cargo items between the hinged walls, and fold flat when not in use so as not to limit cargo storage capacity of the cargo storage area.

An improved e-track connector, or lockdown, is presented that can be installed in single locations instead of provided in tracks as in the industry. It also possesses a finished slot that accepts logistics straps buckles. The slot is a complete rectangle with no excess material folded under it and has been deburred and finished smooth. The device also possesses a drain slot along the side of the tang and drain holes in the buckle receiver such that liquid will drain out of the connector when it is mounted horizontally.

Method and apparatus for handling aerogenerator blades that provide a versatile means for handling aerogenerator blades without an unbalanced distribution of the loads in the blade. The method comprises positioning an upper mounting part (103) over the blade after the upper mold has been retracted; lifting the blade with the upper mounting part from the under mold using a lifting means; positioning the blade over an under mounting part (104) which is fixedly attached to an inferior movable support (102); attaching the upper mounting part to the under mounting part, wherein the upper and under mounting parts together have the inner surface substantially corresponding to the shape of the blade outer profile section. The invention further comprises an apparatus for handling aerogenerator blades.

A protective cap for a trailing edge of a rotor blade of a wind turbine for use during transportation, handling, or maintenance of the rotor blade is disclosed. The protective cap includes a body having a first leg, a second leg, and a cap member. The cap member connects the first and second legs. Further, the cap member may be configured to cover at least a portion of a trailing edge of the rotor blade and may be configured to provide a gap between an inner surface of the protective cap and the trailing edge. In addition, the first and second legs may resiliently engage the rotor blade.

An edge protector for insertion between a load to be lifted and a lifting member which facilitates the lifting of the load, preventing damage to either the load or the lifting member. The edge protector has a pair of flanges which extend from a radiused or curved center portion. Each flange has an inner surface and an outer surface. A portion of each respective outer surface of each flange is spaced from and is essentially parallel to the inner surface of the respective flange.

An apparatus relates generally to a clock generator is disclosed. The clock generator is coupled to receive an input clock signal and further coupled to provide an output clock signal. An address and control register is coupled to receive an address signal and the output clock signal. An access generator is coupled to receive the output clock signal. The clock generator includes: an input node coupled to receive the input clock signal; at least one pulse generator coupled to the input node to receive the input clock signal and further coupled to provide a clock control signal; and a control gate coupled to the input node to receive the input signal and further coupled to the at least one pulse generator to receive the clock control signal. The clock control signal is provided in a non-toggling state for a high-frequency mode and in a toggling state for a low-frequency mode.

A bridge output circuit includes an output terminal, a high side transistor, a low side transistor, a high side driver for controlling a gate voltage of the high side transistor, a low side driver for controlling a gate voltage of the low side transistor, and a controller for controlling the high side and low side drivers. The low side driver includes a first current source, a second current source, and a first assist circuit. The controller is configured to control the turning-on and turning-off states of the first current source, the second current source and the first assist circuit.

A semiconductor integrated circuit includes: a main-interconnect to which supply voltage or reference voltage is applied; a plurality of sub-interconnects; a plurality of circuit cells configured to be connected to the plurality of sub-interconnects; a power supply switch cell configured to control, in accordance with an input control signal, connection and disconnection between the main-interconnect and the sub-interconnect to which a predetermined one of the circuit cells is connected, of the plurality of sub-interconnects; and an auxiliary interconnect configured to connect the plurality of sub-interconnects to each other.

An isolator circuit capable of two-way electrical disconnection and a semiconductor device including the isolator circuit are provided. A data holding portion is provided in an isolator circuit without the need for additional provision of a data holding portion outside the isolator circuit, and data which is to be input to a logic circuit that is in an off state at this moment is stored in the data holding portion. The data holding portion may be formed using a transistor with small off-state current and a buffer. The buffer can include an inverter circuit and a clocked inverter circuit.

Disclosed herein is a device that includes first and second buffer circuits connected to a data terminal and a first control circuit controlling the first and second buffer circuits. The first control circuit receives n pairs of first and second internal data signals complementary to each other from 2n input signal lines and outputs a pair of third and fourth internal data signals complementary to each other to first and second output signal lines, where n is a natural number more than one. The first and second buffer circuits are controlled based on the third and fourth internal data signals such that one of the first and second buffer circuits turns on and the other of the first and second buffer circuits turns off.

A semiconductor device includes an internal circuit, a power supply control circuit which controls supply of a power supply to the internal circuit upon receipt of a first control signal, and a control signal generation circuit which outputs the first control signal upon receipt of a second control signal. The control signal generation circuit does not deactivate the first control signal when an inactive period of the second control signal is equal to or less than a first period and deactivates the first control signal when the inactive period of the second control signal is more than the first period.

An embodiment of this invention uses a massive parallel interconnect fabric (MPIF) at the flipped interface of a core die substrate (having the core logic blocks) and a context die (used for in circuit programming/context/customization of the core die substrate), to produce ASIC-like density and FPGA-like flexibility/programmability, while reducing the time and cost for development and going from prototyping to production, reducing cost per die, reducing or eliminating NRE, and increasing performance. Other embodiments of this invention enable debugging complex SoC through large contact points provided through the MPIF, provide for multi-platform functionality, and enable incorporating FGPA core in ASIC platform through the MPIF. Various examples are also given for different implementations.

A method for configuring the placement of a plurality of storage cells on an integrated circuit includes grouping the plurality of storage cells into a plurality of words, where each of the plurality of words is protected by an error control mechanism. The method also includes placing each of the storage cells on the integrated circuit such that a distance between any two of the storage cells belonging to one of the plurality of words is greater than a minimum distance. The minimum distance is configured such that a probability of any of the plurality of words experiencing multiple radiation induced errors is below a threshold value.

A semiconductor integrated circuit including: a circuit block having an internal voltage line; an annular rail line forming a closed annular line around the circuit block and supplied with one of a power supply voltage and a reference voltage; and a plurality of switch blocks arranged around the circuit block along the annular rail line, the plurality of switch blocks each including a voltage line segment forming a part of the annular rail line and a switch for controlling connection and disconnection between the voltage line segment and the internal voltage line.

A circuit for a single differential-inductor oscillator with common-mode resonance may include a tank circuit formed by coupling a first inductor with a pair of first capacitors; a cross-coupled transistor pair coupled to the tank circuit; and one or more second capacitors coupled to the tank circuit and the cross-coupled transistors. The single differential-inductor oscillator may be configured such that a common mode (CM) resonance frequency (FCM) associated with the single differential-inductor oscillator is at twice a differential resonance frequency (FD) associated with the single differential-inductor oscillator.

The present disclosure relates to nanoresonator oscillators or NEMS (nanoelectromechanical system) oscillators. A circuit for measuring the oscillation frequency of a resonator is provided, comprising a first phase-locked feedback loop locking the frequency of a controlled oscillator at the resonant frequency of the resonator, this first loop comprising a first phase comparator. Furthermore, a second feedback loop is provided which searches for and stores the loop phase shift introduced by the resonator and its amplification circuit when they are locked at resonance by the first loop. The first and the second loops operate during a calibration phase. A third self-oscillation loop is set up during an operation phase. It directly links the output of the controllable phase shifter to the input of the resonator. The phase shifter receives the phase-shift control stored by the second loop.

A resonator element includes a substrate including a first principal surface and a second principal surface respectively forming an obverse surface and a reverse surface of the substrate, and vibrating in a thickness-shear vibration mode, a first excitation electrode disposed on the first principal surface, and a second excitation electrode disposed on the second principal surface, and being larger than the first excitation electrode in a plan view, the first excitation electrode is disposed so as to fit into an outer edge of the second excitation electrode in the plan view, and the energy trap confficient M fulfills 15.5≦M≦36.7.

A resonator element includes a substrate vibrating in a thickness-shear vibration mode, a first excitation electrode disposed on one principal surface of the substrate, and has a shape obtained by cutting out four corners of a quadrangle, and a second excitation electrode disposed on the other principal surface of the substrate, and a ratio (S2/S1) between the area S1 of the quadrangle and the area S2 of the first excitation electrode fulfills 87.7%≦(S2/S1)

A phase locked loop includes a voltage controlled oscillator and a frequency divider or frequency multiplier. The voltage controlled oscillator and the frequency divider/multiplier are coupled together in a stacked configuration. A drive current is supplied to the voltage controlled oscillator. The drive current passes from the voltage controlled oscillator to the frequency divider/multiplier, thereby driving the frequency divider/multiplier with the same drive current that was supplied to the voltage controlled oscillator.

A self-feedback random generator comprises a digital-to-analog converter, a digital oscillator, a frequency-modulating unit and a first D-type flip-flop. The digital-to-analog converter receives a digital random-code signal and the digital random-code signal is converted to corresponding analog random signal. The frequency-modulating unit modulates frequency of first digital oscillating signal so as to increase random of frequency of first digital oscillating signal according to voltage value of the analog random signal, and accordingly outputs a second digital oscillating signal. The first D-type flip-flop receives the second digital oscillating signal and a clock signal, and reads the second digital oscillating signal through utilizing the clock signal so as to outputs the digital random-code signal, wherein frequency of the clock signal is smaller than frequency of the first digital oscillating signal, and random of frequency of the second digital oscillating signal corresponds to random of the digital random-code signal.

There are provided an accumulator-type fractional N-PLL synthesizer for suppressing the fractional spurious caused by periodically switching a frequency division number of a fractional frequency divider, and a control method thereof. In an accumulator-type fractional N-PLL synthesizer (100), a pulse signal proportional to a fractional phase error occurring between a reference signal and an output signal of a fractional divider (112) for feeding back an output of a VCO (115) of an output stage to a preceding stage is generated using an error signal from an accumulator (120). Through the use of the pulse signal, pulse widths of a UP signal and a DN signal output from a phase detector (140) are controlled so as to reduce a fractional phase error occurring between the UP signal and the DN signal. Thus, the fractional spurious caused by periodically switching the frequency division number of the fractional divider (112) is suppressed.

A digitally controlled oscillator has a high-order ΔΣ modulator configured to be of at least an order higher than a first order and configured to input a digital control signal and output a pseudorandom digital output signal, a first-order ΔΣ modulator configured to input the pseudorandom digital output signal and generate a control pulse signal including a pulse width corresponding to the pseudorandom digital output signal, a low pass filter configured to pass a low frequency component of the control pulse signal, and an oscillator configured to generate a high-frequency output signal whose frequency is controlled based on the control pulse signal outputted by the low pass filter so as to be a frequency corresponding to the digital control signal.

An integrated circuit (10) has an internal RC-oscillator (20) for providing an internal clock signal (CLI) having an adjustable oscillator frequency. The integrated circuit (10) further comprises terminals (101, 102) for connecting an external LC tank (30) having a resonance frequency and a calibration circuit (40) which is configured to adjust the oscillator frequency based on the resonance frequency of the LC tank (30) connected during operation of the integrated circuit (10). An internal auxiliary oscillator (46) is connected to the terminals (101, 102) in a switchable fashion and is configured to generate an auxiliary clock signal (CLA) based on the resonance frequency. The calibration circuit (40) comprises a frequency comparator (47) which is configured to determine a trimming word (TRW) based on a frequency comparison of the internal clock signal (CLI) and the auxiliary clock signal (CLA). The LC tank (30) to be connected is an antenna for receiving a radio signal.

The invention concerns an oscillator generating a wave composed of a frequency of on the order of terahertz from a beat of two optical waves generated by a dual-frequency optical source. The oscillator includes a modulator the transfer function of which is non-linear for generating harmonics with a frequency of less than one terahertz for each of the optical waves generated by the dual-frequency optical source, an optical detector able to detect at least one harmonic for each of the optical waves generated by the dual-frequency optical source and transforming the harmonics detected into an electrical signal, a phase comparator for comparing the electrical signal with a reference electrical signal, and a module for controlling at least one element of the dual-frequency optical source with a signal obtained from the signal resulting from the comparison.

A digitally-controlled oscillator includes a base frequency generator having an odd number of base inverters connected end-to-end to generate an output signal that oscillates at a predetermined frequency and a frequency-adjusting unit connected to the base frequency generator. The frequency-adjusting unit includes a first string of switchable inverters connected in series with each other, the switchable inverters having sizes that decrease from an input end of the first string to the output end of the first string.