Abstract: The present invention relates to an external cavity tunable laser and a cavity mode locking method thereof. In an embodiment, an external cavity tunable laser comprises a semiconductor amplifier having a partial reflective film provided on one end and an anti-reflective film provided on the other end, a cavity mirror provided at the anti-reflective end to define an external cavity therebetween, a large-range phasing assembly and a quick phasing assembly provided to adjust the optical length of the external cavity independently, an optical power detector provided to detect the optical power of the light output from the semiconductor amplifier, and a control unit in communication with the optical power detector, the large-range phasing assembly, and the quick phasing assembly.

Abstract: A multicast exchange optical switch includes an input port device including M input ports, an output port device including N output ports, a diffractive beam splitter, an optical focusing component, and a 1×N array of reflective devices. The diffractive beam splitter diffracts each input signal beam from the input ports into at least N directions. The optical focusing component includes a first focusing lens and a second focusing lens. The first focusing lens focuses sub-beams from the respective input ports along the Y-axis direction having the same diffraction order. The second focusing lens focuses on the X-axis direction sub-beams from the same input port having different diffraction orders. The 1×N array of reflective devices is provided at the focal plane of the optical focusing component and each reflective device reflects a sub-beam from any one of the input ports to any one of the output ports.

Abstract: A performance testing device for a multi-channel tunable laser, comprising a collimating and coupling lens, a first beam splitter, a power testing unit, a side-mode suppression ratio testing unit, a wavelength testing unit and a control and drive unit, the power testing unit being positioned in a reflection path of the first beam splitter, the wavelength testing unit being positioned in a transmission path of the first beam splitter, the side-mode suppression ratio testing unit being positioned in a reflection path of the second beam splitter, the control and drive unit being in a control connection with the power testing unit, the side-mode suppression ratio testing unit and the wavelength testing unit.

Abstract: A silicon waveguide coupling alignment apparatus includes a fine adjustment bracket, a stress releasing clamp and a silicon photonic integrated chip force sensor. A silicon photonic integrated chip is fixed on the silicon photonic integrated chip force sensor, at least a part of an optical fiber to be coupled is fixed on one end of the stress releasing clamp, the stress releasing clamp is arranged on the fine adjustment bracket, an end surface of the optical fiber to be coupled is aligned with an end surface of the silicon photonic integrated chip by adjusting a position of the fine adjustment bracket, and a cushioning mechanism is arranged within the stress releasing clamp to cushion a collision force in a direction perpendicular to the end surface of the optical fiber to be coupled. The contact force imposed by the optical fiber on the end surface of the chip can be released by the clamp.

Abstract: A wavelength-tunable external cavity laser comprises a semiconductor optical amplifier chip and a laser external cavity, the laser external cavity comprising a grid filter, a phase adjustor and a silicon-based micro-ring chip, the grid filter and the silicon-based micro-ring chip constituting a wavelength-tunable optical filter which implements wavelength tuning by spectral tuning of the grid filter and/or the silicon-based micro-ring chip. A micro-ring filter in the silicon-based micro-ring chip of the tunable external-cavity laser is manufactured by adopting a mature silicon light technology, which can greatly reduce a manufacturing difficulty of the adjustable filter, and reduce the manufacturing cost of a device. An existing external-cavity adjustable technology platform may be used for smooth transition, so as to improve the degree of integration of this type of device and simplify a preparation process.

Abstract: An arrayed waveguide grating based hybrid integrated laser has an adjustable external cavity. The waveguide includes a semiconductor gain die and an optical waveguide chip. The optical waveguide chip includes an arrayed waveguide grating and an arrayed waveguide reflection-controllable component. A resonant cavity is formed by the output end reflection-controllable arrayed waveguide grating chip and the semiconductor gain die. An output wavelength of the laser can be adjusted by changing a driving condition of the reflection-controllable component. The output wavelength is determined by a center wavelength of each channel of the arrayed waveguide grating.

Abstract: An apparatus for alleviating a nonlinear temperature effect of an arrayed waveguide grating, comprising an integrated optical circuit base for an arrayed waveguide grating chip and an actuator. The integrated optical circuit base includes a first region, a second region and connected by a hinge. The actuator includes two or more actuating rods having a thermal expansion coefficient different from that of the integrated optical circuit base. In different temperature ranges, the first region and the second region are driven by different actuating rods to rotate and/or translate relative to each other, so that the first region and the second region have a nonlinear displacement as the temperature changes, which brings the two parts of the arrayed waveguide grating chip to move relative to each other to accurately compensate drifting of a central wavelength of the arrayed waveguide grating chip in the different temperature ranges.

Abstract: Disclosed is a method for monitoring the wavelength of a tunable laser device of user by local OLT. The method is applied to a wavelength division multiplexing passive optical network framework. The framework comprises an ONU, a first athermal array waveguide grating, a transmission optical fiber, a second athermal array waveguide grating and the OLT, which are sequentially connected. ONU comprises tunable wavelength optical transmitters. The method comprises: starting handshaking is carried out between the OLT and the ONU; and the OLT carries out wavelength drifting monitoring during operation of the ONU. Wavelength adjustment can be carried out on the multi-channel tunable laser device in an external auxiliary monitoring environment, thus channel wavelengths of the multi-channel tunable laser device can be accurately controlled, and the requirement for calibration accuracy of channels of the tunable laser device at the ONU is greatly reduced.

Abstract: Device and method are provided to align and bond a lens array to a PD array with high precision, which can implement aligning and bonding of the lens array automatically. A telescopic rod of the stepping actuator is adjusted until photosensitive areas of the PD array form a clear image on the image acquisition CCD through the lens array, an adjusted distance h1 of the telescopic rod is recorded, and a position coordinate (xn, yn) of center of each circular photosensitive area in the image may be obtained, and a slope k1 of a line connecting the centers of the photosensitive areas is calculated. The telescopic rod is adjusted again, and a slope k2 of a line connecting the centers of the apertures of the lens array is calculated. Based on calculated values ?xn, ?yn, arctan(k1)?arctan(k2), the high-resolution adjustment stage is adjusted to adjust position of the lens array.

Abstract: Disclosed is a method for detecting an OTDR curve tail end event to locate an optical fiber break point in an online mode, comprising following steps: 1, an OTDR emits detection light to an optical fiber operation link, and receives reflection light to form reflection sampling point data containing tail end event; 2, head end reflection point in sampling point is found out; 3, traversal is carried out to find search region end point; 4, segmented line fitting is carried out in region of [search region end point, head end reflection point] in reversed direction, start point of section of line meeting predetermined condition is used as a search region start point; 5, if absolute value of difference between largest sampling value in search region and sampling value of search region start point is larger than second preset threshold value, tail end event is judged as reflection tail end event.

Abstract: A system and method for automatic discovery of an optical cable route. The method comprises: a light source power meter automatically monitoring an attenuation value of an optical cable fiber core, the optical cable fiber core being configured in an optical cable route; when the power meter generates an alarm, determining a level of the optical power alarm and reporting the alarm condition of the optical cable route in real time; and a drive automatically searching for available optical cable routes to provide options of available optical cable routes for real-time allocation of services.

Abstract: A Raman pump laser control apparatus comprises a wavelength division multiplexer, a tap coupler, a photoelectric detector, an analog amplification processing circuit, an analog-to-digital converter, a fast Raman pump control unit, an digital-analog converter, and a Raman pump laser. The fast Raman pump control unit, after having known anticipated output light power of the Raman pump laser, based on a direct relationship between a current anticipated output light power of the Raman pump laser and input digital quantity that is needed by the digital-analog converter, uses a feedforward control mechanism so that actual output light power of the Raman pump laser fastly approximates the anticipated output light power thereof, and then synchronously combines with a feedback control mechanism so that the actual output light power of the Raman pump laser is precisely locked on the anticipated output light power, thereby achieving fast and precise control of the Raman pump laser.

Abstract: Embodiments of the present invention relate to method and device for measuring optical signal-to-noise ratio (OSNR). A method for measuring an OSNR of a signal of interest may comprise: obtaining spectrum of the signal of interest, the spectrum including power spectrum density distribution of the signal of interest in a channel bandwidth B; obtaining spectrum of a comparative signal that has the same spectrum characteristics as but different OSNR than the signal of interest, the spectrum including power spectrum density distribution of the comparative signal in the channel bandwidth B; and calculating the OSNR of the signal of interest by using the spectrum of the signal of interest and the spectrum of a comparative signal.

Abstract: Device and method are provided to align and bond a lens array to a PD array with high precision, which can implement aligning and bonding of the lens array automatically. A telescopic rod of the stepping actuator is adjusted until photosensitive areas of the PD array form a clear image on the image acquisition CCD through the lens array, an adjusted distance h1 of the telescopic rod is recorded, and a position coordinate (xn, yn) of center of each circular photosensitive area in the image may be obtained, and a slope k1 of a line connecting the centers of the photosensitive areas is calculated. The telescopic rod is adjusted again, and a slope k2 of a line connecting the centers of the apertures of the lens array is calculated. Based on calculated values ?xn, ?yn, arctan(k1)-arctan(k2), the high-resolution adjustment stage is adjusted to adjust position of the lens array.

Abstract: A cascade control system of an optical fiber amplifier includes a target setting parameter module, a primary controller, at least one controlled module and a secondary controller corresponding to the controlled module. The control system adopts two or more cascade control loops so that disturbance entering into the secondary loop can be overcome quickly, thereby the dynamic characteristics of the system may be improved. The primary controller aims to coarse adjustment and overall target control, and the secondary controller aims to fine adjustment and quick convergence of a short-term target, so that the control quality of the cascade control system may be further improved. The cascade control system may define the overall control target directly in the primary loop and avoid impact of aging characteristics of some special parameters on the application.

Abstract: A multicast exchange optical switch includes an input port device including M input ports, an output port device including N output ports, a diffractive beam splitter, an optical focusing component, and a 1×N array of reflective devices. The diffractive beam splitter diffracts each input signal beam from the input ports into at least N directions. The optical focusing component includes a first focusing lens and a second focusing lens. The first focusing lens focuses sub-beams from the respective input ports along the Y-axis direction having the same diffraction order. The second focusing lens focuses on the X-axis direction sub-beams from the same input port having different diffraction orders. The 1×N array of reflective devices is provided at the focal plane of the optical focusing component and each reflective device reflects a sub-beam from any one of the input ports to any one of the output ports.

Abstract: A Raman pump laser control apparatus comprises a wavelength division multiplexer, a tap coupler, a photoelectric detector, an analog amplification processing circuit, an analog-to-digital converter, a fast Raman pump control unit, an digital-analog converter, and a Raman pump laser. The fast Raman pump control unit, after having known anticipated output light power of the Raman pump laser, based on a direct relationship between a current anticipated output light power of the Raman pump laser and input digital quantity that is needed by the digital-analog converter, uses a feedforward control mechanism so that actual output light power of the Raman pump laser fastly approximates the anticipated output light power thereof, and then synchronously combines with a feedback control mechanism so that the actual output light power of the Raman pump laser is precisely locked on the anticipated output light power, thereby achieving fast and precise control of the Raman pump laser.

Abstract: A method for compensating for a wavelength shift in a wavelength selective switch (WSS), and a device therefor. The device comprises a fixed seat (301) as well as a rotation beam (304) and a compensation block (302) that have different thermal expansion amounts, the rotation beam (304) and the compensation block (302) being fixedly adhered to the fixed seat (301). In the method, a combined structure of the rotation beam (304) and the compensation block (302) with different thermal expansion amounts is adopted; the combined structure rotates by means of different expansion amounts generated by the rotation beam (304) and the compensation block (302) at the same external temperature, and further drives an optical element of the WSS to rotate, hence compensating for a wavelength shift of the WSS. The method is safe and reliable; the device has a simple structure, and is convenient to encapsulate, is applicable to various WSS optical paths, and does not affect advantages of the optical path structure of the WSS.

Abstract: A hybrid fiber amplifier and method of adjusting gain and gain slope of thereof. The hybrid fiber amplifier comprises: RFA and EDFA that does not comprise variable optical attenuator. The RFA comprises pump signal combiner, pump laser group, out-of-band narrow-band filter, and photodetector. The EDFA comprises input coupler, erbium-doped fiber, output coupler, input photodetector, and output photodetector that are connected in sequence. The hybrid fiber amplifier also comprises control module that coordinates and controls EDFA and/or RFA to adjust gain and/or the gain slope based on desired amplification requirements. The EDFA and/or RFA can be coordinated and controlled by using the control module to achieve desired amplification effect. In addition, the EDFA does not comprise the variable optical attenuator, which avoids problems caused by the variable optical attenuator.

Abstract: A multicast optical switch based on free-space transmission comprises a 1×M input collimator array, a light splitting device, an optical distance compensation device, a spot transformation device, a 1×N output collimator array and a reflector array which are arranged in sequence. The 1×N output collimator array corresponds to reflector array. The light splitting device is provided with a light splitting surface and a reflection surface, and by means of light splitting surface and reflection surface, light splitting and beam splitting of n times are carried out on input signals of 1×M input collimator array, and then N beams of sub-signal light are generated. The optical distance compensation device compensates optical distance differences among M×N sub-signal light beams produced by light splitting device. The M×N sub-signal light beams are focused to be 1×N light spots through light spot conversion device, and then 1×N light spots are reflected to reflector array.