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.

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: Disclosed is a method for detecting an OTDR curve tail end event to locate an optical fibre break point in an online mode, comprising following steps: 1, an OTDR emits detection light to an optical fibre 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: 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: A Raman pump laser control apparatus comprises a wavelength division multiplexer, a tap coupler, a photoelectric detector, an analogue amplification processing circuit, an analogue-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 Raman pump laser control apparatus comprises a wavelength division multiplexer, a tap coupler, a photoelectric detector, an analogue amplification processing circuit, an analogue-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 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.

Abstract: A single-pump multi-wavelength lasing semiconductor Raman pump laser comprises a thermoelectric cooler arranged in a shell; a heat transition bearing platform arranged in the thermoelectric cooler; a semiconductor Raman pump laser tube core arranged on the heat transition bearing platform; and a coupling lens group, a thermistor and a backlight detector that are arranged on the heat transition bearing platform respectively. The pump laser tube core, the backlight detector, the thermistor and the thermoelectric cooler are electrically connected to pins outside a laser tube shell. A pump combination apparatus comprises a first signal transmission fiber, a pump signal combiner and a second signal transmission fiber that are sequentially connected to each other. An input terminal of the pump signal combiner is connected to an output terminal of an isolated polarization beam combiner and depolarizer.

Abstract: A coupling device of an optical waveguide chip and a PD array lens. The coupling device comprises a waveguide chip, a PD array, a heat sink, a waveguide gasket and a substrate. The waveguide gasket and the heat sink are located on the substrate, the PD array is located on the heat sink, and the waveguide chip is provided on the waveguide gasket. A reflection prism is provided in an optical path between the waveguide chip and the PD array. The output light of the waveguide chip is reflected by the reflection prism, and then is received by the PD array. A lens array having a convergence effect is provided in the optical path between the waveguide chip and the PD array. The coupling device can reduce costs and has a simple structure, the assembly process thereof is easy to realize, and the photoelectric conversion efficiency thereof is high.

Abstract: An external-cavity tunable laser with a flexible wavelength grid tuning function comprises a resonant cavity, collimating lenses, an optical isolator, and an output optical fiber. The resonant cavity comprises a semiconductor gain chip, a beam expander collimating lens, a combined liquid crystal tunable filter assembly, and a reflecting mirror. A current injected to the semiconductor gain chip is converted to broadband spontaneously radiating photons through electrical-to-optical conversion, and the photons are spread along a waveguide toward two sides. A part of photons with special frequencies go back and forth multiple times in the resonant cavity to form a laser after a threshold condition is met. The laser is collimated by the collimating lens, passes through the optical isolator, is coupled by the collimating lens, and enters the output optical fiber.

Abstract: An OSNR measuring method, comprising: measuring a spectrum to be measured of an optical signal at a point to be measured of an optical transmission line, and acquiring the comparative spectrum of the optical signal within a channel wavelength range and at an SNR different from the SNR of the point to be measured; respectively integrating, within the channel wavelength range of the optical signal, the spectrum to be measured and the comparative spectrum to obtain total power Pspectrum to be measured and Pcomparative spectrum, and acquiring a noise factor F and a signal scale factor A; calculating, according to the total power, the noise factor and the signal scale factor, the noise power Pspectrum to be measured within the channel wavelength range of the optical signal, so as to obtain an OSNR of the point to be measured.

Abstract: This invention involves and discloses a heat control device for power equipment, which comprises heat source, heat sink base plate, heat insulation layer, dissipation heat sink and thermal control switch, wherein the heat source is placed on and in contact with dissipation heat sink, and its bottom is in direct lap joint with heat sink base plate, wherein the heat insulation layer is set around heat sink base plate, wherein the thermal control switch is placed on heat sink base plate. This invention of heat control device is one that demonstrates excellent low temperature thermal insulation property for key components or heat-sensitive elements of power equipment. The heat control device applying technical solutions described in this invention features easy manufacturing, low cost and reliable performance.

Abstract: An external-cavity tunable laser with a flexible wavelength grid tuning function comprises a resonant cavity, collimating lenses, an optical isolator, and an output optical fiber. The resonant cavity comprises a semiconductor gain chip, a beam expander collimating lens, a combined liquid crystal tunable filter assembly, and a reflecting mirror. A current injected to the semiconductor gain chip is converted to broadband spontaneously radiating photons through electrical-to-optical conversion, and the photons are spread along a waveguide toward two sides. A part of photons with special frequencies go back and forth multiple times in the resonant cavity to form a laser after a threshold condition is met. The laser is collimated by the collimating lens, passes through the optical isolator, is coupled by the collimating lens, and enters the output optical fiber.

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 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 single-pump multi-wavelength lasing semiconductor Raman pump laser comprises a thermoelectric cooler arranged in a shell; a heat transition bearing platform arranged in the thermoelectric cooler; a semiconductor Raman pump laser tube core arranged on the heat transition bearing platform; and a coupling lens group , a thermistor and a backlight detector that are arranged on the heat transition bearing platform respectively. The pump laser tube core, the backlight detector, the thermistor and the thermoelectric cooler are electrically connected to pins outside a laser tube shell. A pump combination apparatus comprises a first signal transmission fiber, a pump signal combiner and a second signal transmission fiber that are sequentially connected to each other. An input terminal of the pump signal combiner is connected to an output terminal of an isolated polarization beam combiner and depolarizer.

Abstract: An embodiment of the present invention discloses a method of performing target Raman gain locking and a Raman fiber amplifier. The Raman fiber amplifier comprises a coupler (1) and a control unit (15), wherein the control unit comprises a target gain locking module. A detection circuit formed by filters and optical power detectors is connected between an output side of the coupler (1) and an input side of the control unit (15). Said method uses the control unit (15) to adjust power of the pump laser, making the detected out-of-band ASE power value reach target out-of-band ASE optical signal power value. Thus, the target amplification gain locking can be realized. Optical path according to embodiments of the present invention has a simple structure. The Raman gain can be configured flexibly according to line condition, and automatic control and locking of gain of the Raman fiber amplifier can be realized.

Abstract: A wavelength selective switch (WSS) with hitless switching. The WSS includes the fiber collimator array, the focusing lens, collimating lens, diffraction grating, focusing lens, and attenuation reflection unit array. Each attenuation reflection unit has an interconnected transmission-type MEMS attenuator and a one-dimension MEMS reflector. The transmission-type MEMS attenuator is positioned in the front of the one-dimension MEMS reflector. The central axis of the transmission-type MEMS attenuator aligns and coincides with that of the one-dimension MEMS reflector, with the two central axes being glued together. The WSS of the present invention effectively utilizes the combination of a one-dimension reflector array and a transmission-type optical attenuator chip. With the use of one-dimension reflector array, instead of the known two-dimension reflector array, the complexity of design and manufacture is greatly reduced, thereby reducing the production costs of the switch.

Abstract: The tunable optical filter is provided, comprising an optical means for separating an input optical signal into a tunable drop optical signal and an output optical signal, wherein the output optical signal is directed back along the same path as the input optical signal. One embodiment of the invention comprises an optical circulator, a pair of polarization beam splitters, a pair of half-wave plates, an optical thin-film filter, a rotatable mirror, a spatially fixed mirror. Optical wavelengths are selected by making angular adjustments to the optical thin-film filter and the rotatable mirror, which are rotated by the same angle. A corresponding method for spectrally splitting and spatially separating an input optical signal into an output optical signal and a drop optical signal is also provided.