Ultra-wideband light generation device and method based on microwave photon filter

Abstract

The invention belongs to the field of optical fiber signal spectrum parameter testing, and relates to an ultra-wideband light generation device and method based on a microwave photonic filter. The device comprises a main control unit, and a broadband light generation unit and an active tuning narrowband filtering unit which are connected with the main control unit, the broadband light generation unit and the active tuning narrowband filtering unit are connected through an optical isolator. The main control unit comprises an embedded system and is configured to be used for controlling the ultra-wideband light generation process and setting working parameters; the broadband light generation unit is configured to be used for generating an ultra-broadband light signal; the active tuning narrowband filtering unit is configured to be used for performing ultra-narrowband active tuning filtering on the ultra-wideband optical signal generated by the wideband optical generation unit, and generating frequency sweeping light capable of performing frequency domain scanning with a configurable ultra-narrow bandwidth in an ultra-wideband range; the generation of signal light with active tunable ultra-narrow sweep frequency bandwidth and ultra-wide frequency band range is realized.

Description

Technical Field

[0001] The invention belongs to the field of optical fiber signal spectrum parameter testing, and in particular relates to an ultra-wideband light generating device and method based on a microwave photon filter. Background Art

[0002] Ultra-wideband optical generation is one of the key elements for the measurement and analysis of optical frequency domain multi-dimensional parameters, such as the spectrum, frequency response, phase, amplitude, delay and other multi-dimensional spectrum parameters of optical fiber signals, and the frequency domain parameter test of optoelectronic devices. In addition, ultra-wideband optical generation also has a wide range of value in the fields of microwave photonics, intelligent photonics, microsystems, fiber-borne radio frequency, and optically generated microwave signals.

[0003] For example, in the application field of spectrum analysis of optical signals of optical fiber devices and optical fiber systems, spectral response is an important parameter to reveal the characteristic functions and potential applications of optical materials, devices and systems. In particular, with the development, testing and application of broadband high-precision optical devices and core photonic integrated chips, the rapid development of photonic technology, the continuous innovation of cutting-edge disciplines, and the rapid development and application of new generation optical information technologies such as optical communications, optical sensing, and optical information processing, the optical domain direct measurement of broadband spectrum, phase, amplitude, delay and other multi-dimensional spectrum parameters has put forward the need for broadband high-resolution measurement and analysis.

[0004] The existing methods for generating test light have limitations. For example, methods based on optical micro-ring cavities, fiber phase-locked loops, nonlinear effects, light injection methods, or optical heterodynes can only generate ultra-wideband test light with large filter bandwidth and non-tunable characteristics. For example, methods based on optoelectronic oscillators, optical combs, external modulation methods, or electro-optical modulation schemes can only generate ultra-narrow filter bandwidth but limited frequency band test light. Existing methods cannot generate signal light with actively tunable ultra-narrow filter bandwidth and ultra-wideband required for multi-dimensional spectrum parameter testing. Summary of the invention

[0005] In view of the above technical problems, the present invention provides an ultra-wideband light generating device and method based on a microwave photon filter. For optical fiber signals, ultra-wideband light is first generated by adopting the heterodyne principle, and then an actively tuned ultra-narrowband filter constructed based on the stimulated Brillouin principle generates continuously changing ultra-narrowband swept-frequency light, thereby realizing the generation of signal light with actively tunable ultra-narrow swept-frequency bandwidth and ultra-wide frequency band range.

[0006] The present invention is achieved through the following technical solutions: An ultra-wideband light generating device based on a microwave photon filter, the ultra-wideband light generating device comprising a main control unit, a wideband light generating unit connected to the main control unit, and an actively tuned narrowband filtering unit; the wideband light generating unit and the actively tuned narrowband filtering unit are connected via an optical isolator; The main control unit includes an embedded system configured for control and operating parameter setting of the ultra-wideband light generation process; The broadband light generating unit is configured to generate an ultra-broadband optical signal of 1 GHz to 500 GHz; The actively tuned narrowband filtering unit is configured to perform ultra-narrowband active tuning filtering on the ultra-wideband optical signal generated by the wideband optical generating unit, thereby generating narrowband swept frequency light that performs frequency domain scanning in an ultra-wideband range of 1 GHz to 500 GHz with a configurable bandwidth of 1 MHz to 100 MHz.

[0007] Furthermore, the optical devices used by the main control unit, the broadband light generating unit, and the actively tuned narrowband filtering unit are all optical fiber devices.

[0008] Further, the broadband light generating unit comprises: a frequency-stabilized single-frequency laser, a first polarization controller, an optical mixer, a second polarization controller, a tunable DFB laser, and a frequency stabilization & wavelength tuning control module; The frequency-stabilized single-frequency laser, the first polarization controller and the optical mixer are connected in sequence; the frequency stabilization & wavelength tuning control module, the tunable DFB laser, the second polarization controller and the optical mixer are connected in sequence.

[0009] Further, the frequency-stabilized single-frequency laser is configured to generate frequency-stabilized linearly polarized light of a single wavelength, that is, to generate the signal light required by the ultra-wideband light generating device; The tunable DFB laser is configured to generate single-wavelength frequency-stabilized linearly polarized light having a wavelength deviation from the output light of the frequency-stabilized single-frequency laser, that is, to generate the local oscillator light required by the ultra-wideband light generating device; The frequency stabilization & wavelength tuning control module adopts a frequency stabilization and wavelength tuning scheme based on linear absorption frequency modulation spectrum, and is configured for frequency stabilization and wavelength tuning control of the tunable DFB laser, and is used to control the tunable DFB laser to output a single-wavelength frequency-stabilized polarized light with tunable wavelength; The first polarization controller is configured to adjust the polarization state of the output light of the frequency-stabilized single-frequency laser, and the first polarization controller outputs the signal light after the polarization state is adjusted; The second polarization controller is configured to adjust the polarization state of the output light of the tunable DFB laser, and the second polarization controller outputs the local oscillator light after the polarization state is adjusted; The optical mixer is configured to generate an ultra-wideband optical signal by heterodyning the local oscillator light and the signal light whose polarization states are consistent after polarization state adjustment.

[0010] Furthermore, the polarization state of the local oscillator light after the polarization state is adjusted matches the polarization state of the signal light after the polarization state is adjusted.

[0011] Further, the actively tuned narrowband filtering unit includes a third polarization controller, an optical fiber ring, an optical circulator, a fourth polarization controller, an optical amplifier, and a tunable laser; The third polarization controller is connected to the broadband light generating unit via an optical isolator; the third polarization controller, the optical fiber ring and the optical circulator are connected in sequence; the tunable laser, the optical amplifier, the fourth polarization controller and the optical circulator are connected in sequence.

[0012] Further, the tunable laser is configured to generate a swept frequency pump light with a continuously changing wavelength required for stimulated Brillouin effect of the optical fiber, and the output light of the tunable laser is a linearly polarized light; The optical amplifier is configured to amplify the pump light output by the tunable laser in a power-configurable manner; a fourth polarization controller configured to adjust the polarization state of the pump light amplified by the optical amplifier; A third polarization controller is configured to adjust the polarization state of the ultra-wideband optical signal output by the broadband light generating unit; the polarization state of the pump light after polarization state adjustment output by the fourth polarization controller matches the polarization state of the ultra-wideband optical signal after polarization state adjustment output by the third polarization controller; An optical fiber ring is configured to generate a stimulated Brillouin effect between the polarization-adjusted pump light output by the fourth polarization controller and the polarization-adjusted ultra-wideband optical signal output by the third polarization controller in the optical fiber ring, thereby generating an ultra-narrowband swept-frequency light within a wide frequency band; The optical circulator is configured to introduce the polarization-adjusted pump light output by the fourth polarization controller and the ultra-wideband optical signal output by the third polarization controller into the optical fiber ring, and to export the backscattered light generated by the stimulated Brillouin effect in the optical fiber ring, that is, to export the ultra-narrowband swept light, so as to realize ultra-narrowband filtering of the ultra-wideband optical signal.

[0013] Furthermore, the optical fiber ring adopts bismuth-doped optical fiber or chalcogenide glass optical fiber. Compared with other optical fibers, bismuth-doped optical fiber or chalcogenide glass optical fiber has better Brillouin effect.

[0014] A method for generating ultra-wideband light based on a microwave photon filter, using the ultra-wideband light generating device based on a microwave photon filter according to any one of claims 1 to 8, the method comprising the following steps: (1) In the broadband light generating unit, a frequency-stabilized single-frequency laser generates single-wavelength frequency-stabilized linearly polarized light as signal light, and the polarization state of the signal light is adjusted by a first polarization controller; (2) In the broadband light generating unit, under the control of the frequency stabilization & wavelength tuning control module, the tunable DFB laser generates a single-wavelength frequency-stabilized linearly polarized light having a wavelength deviation from the output light of the frequency-stabilized single-frequency laser as the local oscillator light, and the polarization state of the local oscillator light is adjusted by the second polarization controller; the polarization state of the local oscillator light after the polarization state is adjusted matches the polarization state of the signal light after the polarization state is adjusted; (3) In the broadband light generating unit, the signal light with matched polarization states and the local oscillator light are heterodyned in the optical mixer to generate an ultra-broadband optical signal. The ultra-broadband optical signal enters the active tuning narrowband filtering unit through the optical isolator. The ultra-broadband optical signal generated in this step is continuously tuned and filtered by the active tuning ultra-narrowband filter constructed based on the stimulated Brillouin principle to generate an ultra-narrowband swept frequency light of the MHz level with a continuously changing center frequency. (4) In the actively tuned narrowband filter unit, the ultra-wideband optical signal generated in step (3) is polarized by a third polarization controller, and the third polarization controller outputs the ultra-wideband optical signal after the polarization state is adjusted; (5) In the actively tuned narrowband filter unit, the swept frequency pump light with continuously changing wavelength generated by the tunable laser is amplified in a power-configurable manner by the optical amplifier, and then the polarization state is adjusted by the fourth polarization controller, and the polarization state of the pump light after the polarization state adjustment output by the fourth polarization controller matches the polarization state of the ultra-wideband optical signal after the polarization state adjustment output by the third polarization controller; (6) In the actively tuned narrowband filter unit, the swept pump light after polarization state adjustment output by the fourth polarization controller and the ultra-wideband optical signal after polarization state adjustment output by the third polarization controller enter the optical fiber ring through the optical circulator to produce stimulated Brillouin effect, thereby generating an ultra-narrowband swept light of the MHz order with a center frequency that continuously changes within a wide bandwidth. The ultra-narrowband swept light is output through the optical circulator, thereby realizing the generation of actively tunable ultra-narrow filter bandwidth and ultra-wideband signal light.

[0015] Beneficial technical effects of the present invention: (1) The ultra-wideband light generating device based on a microwave photon filter provided by the present invention can generate signal light with an ultra-wide frequency band range of the order of GHz and a frequency sweep bandwidth of the order of MHz, thus solving the problem that a wide coverage frequency band and an ultra-narrow frequency sweep bandwidth cannot be achieved at the same time.

[0016] (2) The ultra-wideband light generating device based on the microwave photon filter provided by the present invention does not require complicated and expensive devices and complex control and adjustment technologies, and has the characteristics of simple structure and good feasibility.

[0017] (3) The ultra-wideband light generation method based on the microwave photon filter provided by the present invention can generate actively tunable ultra-narrow filtering bandwidth and ultra-wideband signal light, which can be conveniently converted into photoelectricity by a high-speed photodetector, thereby generating GHz or even THz-level ultra-wideband and MHz-level scanning bandwidth radio frequency signals.

[0018] (4) The ultra-wideband light generating device based on the microwave photon filter provided by the present invention can flexibly configure the sweep bandwidth of the generated signal light between several MHz and several hundred MHz.

[0019] (5) The ultra-wideband light generating device based on the microwave photon filter provided by the present invention can generate an actively tunable ultra-narrow filtering bandwidth and an ultra-wideband signal light, which can be connected to an electro-optical modulation sweeping unit to realize a signal light with a sweeping bandwidth of kHz or even narrower. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of an ultra-wideband light generating device based on a microwave photon filter in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] On the contrary, the present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention as defined by the claims. Further, in order to make the public have a better understanding of the present invention, some specific details are described in detail in the detailed description of the present invention below. Those skilled in the art can fully understand the present invention without the description of these details.

[0023] Example 1: Figure 1 As shown, an ultra-wideband light generating device based on a microwave photon filter, the ultra-wideband light generating device comprises a main control unit, a wideband light generating unit respectively connected to the main control unit, and an actively tuned narrowband filtering unit; the wideband light generating unit and the actively tuned narrowband filtering unit are connected via an optical isolator; The main control unit includes an embedded system configured for control and operating parameter setting of the ultra-wideband light generation process; In this embodiment, the main control unit may adopt a microprocessor or ARM-based CPU module, such as a CPU module launched by Advantech, ADLINK, etc.

[0024] The broadband light generating unit is configured to generate an ultra-broadband optical signal of 1 GHz to 500 GHz; The actively tuned narrowband filtering unit is configured to perform ultra-narrowband active tuning filtering on the ultra-wideband optical signal generated by the wideband optical generating unit, thereby generating narrowband swept frequency light that performs frequency domain scanning in an ultra-wideband range of 1 GHz to 500 GHz with a configurable bandwidth of 1 MHz to 100 MHz.

[0025] In this embodiment, the optical devices used by the main control unit, the broadband light generating unit, and the actively tuned narrowband filtering unit are all optical fiber devices.

[0026] In this embodiment, the broadband light generating unit comprises: a frequency-stabilized single-frequency laser, a first polarization controller, an optical mixer, a second polarization controller, a tunable DFB laser, and a frequency stabilization & wavelength tuning control module; The frequency-stabilized single-frequency laser, the first polarization controller and the optical mixer are connected in sequence; the frequency-stabilized & wavelength tuning control module, the tunable DFB laser, the second polarization controller and the optical mixer are connected in sequence. Specifically, the frequency-stabilized single-frequency laser and the first polarization controller are connected via an optical fiber jumper and a flange; the first polarization controller and the optical mixer are connected via an optical fiber jumper and a flange; the frequency-stabilized & wavelength tuning control module and the tunable DFB laser are connected via an optical fiber jumper and a flange; the tunable DFB laser and the second polarization controller are connected via an optical fiber jumper and a flange; the second polarization controller and the optical mixer are connected via an optical fiber jumper and a flange; the optical mixer and the active tuning narrowband filter unit are connected via the optical isolator.

[0027] In this embodiment, the frequency-stabilized single-frequency laser is configured to generate frequency-stabilized linearly polarized light of a single wavelength, that is, to generate the signal light required by the ultra-wideband light generating device; The tunable DFB laser is configured to generate single-wavelength frequency-stabilized linearly polarized light having a wavelength deviation from the output light of the frequency-stabilized single-frequency laser, that is, to generate the local oscillator light required by the ultra-wideband light generating device; The frequency stabilization & wavelength tuning control module is configured to control the frequency stabilization and wavelength tuning of the tunable DFB laser, and is used to control the tunable DFB laser to output a single-wavelength frequency-stabilized polarized light with tunable wavelength; thereby generating a local oscillator light with a tunable wavelength deviation from the output light of the frequency-stabilized single-frequency laser; In this embodiment, the frequency stabilization & wavelength tuning control module includes a 1:99 optical splitter, an HCN gas chamber, a photodetector, and a temperature-frequency stabilization & wavelength tuning control circuit board connected to the DFB laser in sequence, and the frequency stabilization & wavelength tuning control circuit board is connected to the DFB laser through a DFB laser driver, wherein 99% of the light output by the DFB laser through the 1:99 optical splitter enters the second polarization controller, and 1% of the light output by the 1:99 optical splitter is used for frequency stabilization & wavelength tuning control. A frequency stabilization and wavelength tuning scheme based on linear absorption frequency modulation spectrum is adopted, and the maximum value of the slope of the absorption spectrum line generated by the HCN gas chamber of the 1% of the light output by the DFB laser through the 1:99 optical splitter is used as the reference point of the feedback control signal to perform frequency stabilization control on the frequency of the laser signal output by the DFB laser. Using the maximum value of the slope of the absorption spectrum line can greatly improve the sensitivity and accuracy of the feedback control, and can achieve tunable DFB laser output 10 -9 The laser signal has a stability of the order of 10000 and the wavelength tuning of the output laser signal has a tuning deviation less than the order of MHz; The first polarization controller is configured to adjust the polarization state of the output light of the frequency-stabilized single-frequency laser, and the first polarization controller outputs the signal light after the polarization state is adjusted; The second polarization controller is configured to adjust the polarization state of the output light of the tunable DFB laser, and the second polarization controller outputs the local oscillator light after the polarization state is adjusted; The optical mixer is configured to generate an ultra-wideband optical signal by heterodyning the local oscillator light after polarization state adjustment and the signal light after polarization state adjustment.

[0028] In this embodiment, the polarization state of the local oscillator light after polarization state adjustment matches the polarization state of the signal light after polarization state adjustment.

[0029] In this embodiment, the actively tuned narrowband filtering unit includes a third polarization controller, an optical fiber ring, an optical circulator, a fourth polarization controller, an optical amplifier, and a tunable laser; The third polarization controller is connected to the broadband light generating unit through an optical isolator, and the third polarization controller, the optical fiber ring and the optical circulator are connected in sequence; the tunable laser, the optical amplifier, the fourth polarization controller and the optical circulator are connected in sequence. Specifically, the third polarization controller is connected to the optical fiber ring through an optical fiber jumper and a flange; the optical fiber ring is connected to the optical circulator through an optical fiber jumper and a flange; the optical circulator is connected to the fourth polarization controller through an optical fiber jumper and a flange; the fourth polarization controller is connected to the optical amplifier through an optical fiber jumper and a flange; the optical amplifier is connected to the tunable laser through an optical fiber jumper and a flange.

[0030] In this embodiment, the tunable laser is configured to generate a swept frequency pump light with a continuously changing wavelength required for stimulated Brillouin effect of the optical fiber, and the output light of the tunable laser is a linearly polarized light; The optical amplifier is configured to amplify the pump light output by the tunable laser in a power-configurable manner, so as to realize the configurable filtering bandwidth of the actively tuned ultra-narrowband filter constructed based on the stimulated Brillouin effect of the optical fiber; A fourth polarization controller is configured to adjust the polarization state of the pump light amplified by the optical amplifier; a third polarization controller is configured to adjust the polarization state of the ultra-wideband optical signal output by the broadband optical generating unit; the polarization state of the pump light after the polarization state adjustment output by the fourth polarization controller matches the polarization state of the ultra-wideband optical signal after the polarization state adjustment output by the third polarization controller; An optical fiber ring is configured to generate a stimulated Brillouin effect between the polarization-adjusted pump light output by the fourth polarization controller and the polarization-adjusted ultra-wideband optical signal output by the third polarization controller in the optical fiber ring, thereby generating an ultra-narrowband swept-frequency light within a wide frequency band; The optical circulator is configured to introduce the polarization-adjusted pump light output by the fourth polarization controller and the ultra-wideband optical signal output by the third polarization controller into the optical fiber ring, and to export the backscattered light generated by the stimulated Brillouin effect in the optical fiber ring, that is, the ultra-narrowband filtered light, to achieve ultra-narrowband filtering of the ultra-wideband optical signal.

[0031] Preferably, the polarization states of the output lights of the first polarization controller and the second polarization controller match and are free of stray light; the polarization states of the output lights of the third polarization controller and the fourth polarization controller match and are free of stray light.

[0032] Preferably, in this embodiment, the frequency-stabilized single-frequency laser can adopt polarization-maintaining output narrow-linewidth lasers such as Koheras of NKT, OE40 series of OEWaves, and companies such as NeoPhotonics, II-VI, MKS, iXblue, RIO Laser, MPB, TeraXion, EblanaPhotonics, Orbits LightWave, ID Photonics, Shanghai Hanyu, Zhuhai Hengqin Donghui, Pinzhun Laser, Gaoyue Technology, Ziguan Technology, and Zhongke Ruize; the tunable DFB laser can adopt polarization-maintaining output narrow-linewidth tunable lasers such as E15 of NKT, and companies such as Lumentum, NTT, Bookham, Coherent, Oclaro, Hamamatsu Hanfu Optoelectronics, Innolight, Innolight, Hisense, Hangzhou Lantop, and Lianguang.

[0033] Preferably, the optical mixer is a polarization-maintaining optical mixer with polarization diversity; Preferably, the polarization controller preferably adopts a four-channel electrically controlled polarization controller; Preferably, the optical fiber ring uses special optical fibers with optimized Brillouin effect, such as bismuth-doped optical fibers and chalcogenide glass optical fibers, to meet the requirements of MHz-level ultra-narrow bandwidth, high dynamic range, and active tuning filtering without spurious. Preferably, the optical fiber amplifier preferably adopts an erbium-doped optical fiber amplifier, which can generate an amplified optical output with an adjustable gain of more than ten dBm, fully meeting the requirements of the active tuning narrowband filter unit for the pump optical power; Preferably, the optical circulator preferably adopts a polarization-maintaining optical fiber circulator commonly used in the optical communication band; Preferably, the tunable laser can be a tunable laser with polarization-maintaining output and wide wavelength tuning range such as Keysight's 81606A, Newport's 8800 series, CIS's 6371A, and EXFO, Santec, VIAVI, OPTICA, MKS, LUNA, APEX and other companies.

[0034] The working principle of the ultra-wideband light generating device based on the microwave photon filter proposed in this embodiment is as follows: Under the control of the main control unit, a microwave photon filter based on heterodyne and stimulated Brillouin principle is used. For optical fiber signals, ultra-wideband light is first generated by using the heterodyne principle, and then the actively tuned ultra-narrowband filter based on the stimulated Brillouin principle generates continuously changing ultra-narrowband swept light, thereby realizing the generation of signal light with actively tunable ultra-narrow swept bandwidth and ultra-wide frequency range.

[0035] Embodiment 2: A method for generating ultra-wideband light based on a microwave photon filter, using the ultra-wideband light generating device based on a microwave photon filter described in Embodiment 1, the method comprising the following steps: (1) In the broadband light generating unit, the frequency-stabilized single-frequency laser generates a single-wavelength frequency-stabilized linearly polarized light as the signal light, and the polarization state of the signal light is adjusted by the first polarization controller; preferably, in this embodiment, the frequency-stabilized single-frequency laser generates a single-wavelength frequency-stabilized linearly polarized light of 1550nm, 10kHz linewidth, and p polarization state as the signal light; and the polarization state thereof is adjusted by the first polarization controller to maintain the p polarization state, so as to match the polarization state of the local oscillator light of the tunable DFB laser adjusted by the second polarization controller; (2) In the broadband light generating unit, under the control of the frequency stabilization & wavelength tuning control module, the tunable DFB laser generates a single-wavelength frequency-stabilized linearly polarized light having a wavelength deviation from the output light of the frequency-stabilized single-frequency laser as the local oscillator light, and the polarization state of the local oscillator light is adjusted by the second polarization controller; the polarization state of the local oscillator light after the polarization state is adjusted matches the polarization state of the signal light after the polarization state is adjusted; Preferably, in this embodiment, under the control of the frequency stabilization & wavelength tuning control module, the tunable DFB laser outputs a single-wavelength frequency-stabilized linearly polarized light of 1550.4 nm, 20 kHz line width, and p polarization state, and the output light has a wavelength deviation from the output light of the frequency-stabilized single-frequency laser, and is used as the local oscillator light, and its polarization state is adjusted by the second polarization controller to maintain the p polarization state, so as to match the polarization state of the signal light of the frequency-stabilized single-frequency laser adjusted by the first polarization controller; (3) In the broadband light generating unit, the signal light and the local oscillator light with matched polarization states are heterodyned in the optical mixer to generate an ultra-broadband optical signal, which then enters the actively tuned narrowband filtering unit through the optical isolator. Preferably, the signal light and the local oscillator light with matched polarization states are heterodyned in the optical mixer to generate an ultra-wideband optical signal of 50 GHz.

[0036] Preferably, by adjusting the wavelength difference between the laser signal output by the frequency-stabilized single-frequency laser in step (1) and the laser signal output by the tunable DFB laser in step (2), ultra-wideband optical signals in different ranges of 1 GHz to 500 GHz can be generated; (4) In the actively tuned narrowband filter unit, the ultra-wideband optical signal generated in step (3) is polarized by a third polarization controller, and the third polarization controller outputs the ultra-wideband optical signal after polarization state adjustment; (5) In the actively tuned narrowband filter unit, the swept frequency pump light with continuously changing wavelength generated by the tunable laser is amplified in a power-configurable manner by the optical amplifier, and then the polarization state is adjusted by the fourth polarization controller, and the polarization state of the pump light after the polarization state adjustment output by the fourth polarization controller matches the polarization state of the ultra-wideband optical signal after the polarization state adjustment output by the third polarization controller; Preferably, the tunable laser generates a swept frequency pump light with a wavelength continuously changing in the range of 1550.2001nm to 1550.6001nm, a line width of 100kHz, and a p-polarization state, which is amplified to 10dBm by an optical amplifier, and its polarization state is adjusted by a fourth polarization controller to maintain the p-polarization state, so as to match the polarization state of the ultra-wideband light output by the wide-band light generating unit adjusted by the third polarization controller; (6) In the actively tuned narrowband filter unit, the polarization-adjusted pump light output by the fourth polarization controller and the polarization-adjusted ultra-wideband optical signal output by the third polarization controller enter the optical fiber ring through the optical circulator to generate stimulated Brillouin effect, thereby generating an ultra-narrowband swept-frequency light of the MHz order with a center frequency that continuously changes within a wide-band range. The ultra-narrowband swept-frequency light is output through the optical circulator, thereby realizing the generation of actively tunable ultra-narrow filter bandwidth and ultra-wideband signal light.

[0037] Preferably, by changing the wavelength tuning range of the tunable laser and the power of the swept-frequency pump light after passing through the optical amplifier, a swept-frequency light with an ultra-narrow bandwidth of 1 MHz to 100 MHz configurable bandwidth for frequency domain scanning can be achieved.

[0038] The method provided by the present invention generates ultra-wideband light by adopting the heterodyne principle, and then generates continuously changing ultra-narrowband swept-frequency light by actively tuning ultra-narrowband filters constructed based on the stimulated Brillouin principle, thereby realizing the generation of signal light with ultra-narrow swept-frequency bandwidth and ultra-wideband coverage, and can generate swept-frequency light that performs frequency domain scanning with an ultra-narrow bandwidth of 1MHz to 100MHz configurable bandwidth within an ultra-wideband range of 1GHz to 500GHz. Thus, suitable test light is provided for multi-dimensional spectrum parameter testing of high-speed optical modulation signal light. The ultra-wideband optical signal generated by the present invention can be applied to the fields of optoelectronic devices and multi-dimensional spectrum parameter measurement of optical fiber signals, microwave photonics, fiber-borne radio frequency, photon integration, etc.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An ultra-wideband light generating device based on a microwave photon filter, characterized in that: The ultra-wideband light generating device comprises a main control unit, a wideband light generating unit connected to the main control unit, and an actively tuned narrowband filtering unit; the wideband light generating unit and the actively tuned narrowband filtering unit are connected via an optical isolator; The main control unit is configured to control the ultra-wideband light generation process and set working parameters; The broadband light generating unit is configured to generate an ultra-broadband optical signal of 1 GHz to 500 GHz; The actively tuned narrowband filtering unit is configured to perform ultra-narrowband active tuning filtering on the ultra-wideband optical signal generated by the wideband optical generating unit, thereby generating narrowband swept frequency light that performs frequency domain scanning in an ultra-wideband range of 1 GHz to 500 GHz with a configurable bandwidth of 1 MHz to 100 MHz.

2. The ultra-wideband light generating device based on a microwave photon filter according to claim 1, characterized in that: The optical devices used by the main control unit, the broadband light generating unit, and the actively tuned narrowband filtering unit are all optical fiber devices.

3. The ultra-wideband light generating device based on a microwave photon filter according to claim 1, characterized in that: The broadband light generating unit comprises: a frequency-stabilized single-frequency laser, a first polarization controller, an optical mixer, a second polarization controller, a tunable DFB laser, and a frequency-stabilization & wavelength tuning control module; The frequency-stabilized single-frequency laser, the first polarization controller and the optical mixer are connected in sequence; the frequency stabilization & wavelength tuning control module, the tunable DFB laser, the second polarization controller and the optical mixer are connected in sequence.

4. The ultra-wideband light generating device based on a microwave photon filter according to claim 3, characterized in that: The frequency-stabilized single-frequency laser is configured to generate frequency-stabilized linearly polarized light of a single wavelength, that is, to generate the signal light required by the ultra-wideband light generating device; The tunable DFB laser is configured to generate single-wavelength frequency-stabilized linearly polarized light having a wavelength deviation from the output light of the frequency-stabilized single-frequency laser, that is, to generate the local oscillator light required by the ultra-wideband light generating device; The frequency stabilization & wavelength tuning control module is configured to be used for frequency stabilization and wavelength tuning control of the tunable DFB laser, and is used to control the tunable DFB laser to output a single-wavelength frequency-stabilized polarized light with tunable wavelength; The first polarization controller is configured to adjust the polarization state of the output light of the frequency-stabilized single-frequency laser, and the first polarization controller outputs the signal light after the polarization state is adjusted; The second polarization controller is configured to adjust the polarization state of the output light of the tunable DFB laser, and the second polarization controller outputs the local oscillator light after the polarization state is adjusted; The optical mixer is configured to generate an ultra-wideband optical signal by heterodyning the local oscillator light and the signal light whose polarization states are consistent after polarization state adjustment.

5. The ultra-wideband light generating device based on a microwave photon filter according to claim 4, characterized in that: The polarization state of the local oscillator light after the polarization state is adjusted matches the polarization state of the signal light after the polarization state is adjusted.

6. The ultra-wideband light generating device based on a microwave photon filter according to claim 1, characterized in that: The active tuning narrowband filtering unit includes a third polarization controller, an optical fiber ring, an optical circulator, a fourth polarization controller, an optical amplifier, and a tunable laser; The third polarization controller is connected to the broadband light generating unit via an optical isolator; the third polarization controller, the optical fiber ring and the optical circulator are connected in sequence; the tunable laser, the optical amplifier, the fourth polarization controller and the optical circulator are connected in sequence.

7. The ultra-wideband light generating device based on a microwave photon filter according to claim 6, characterized in that: The tunable laser is configured to generate a swept frequency pump light with a continuously changing wavelength required for stimulated Brillouin effect in optical fiber; The optical amplifier is configured to amplify the pump light output by the tunable laser in a power-configurable manner; a fourth polarization controller configured to adjust the polarization state of the pump light amplified by the optical amplifier; A third polarization controller is configured to adjust the polarization state of the ultra-wideband optical signal output by the broadband light generating unit; the polarization state of the pump light after polarization state adjustment output by the fourth polarization controller matches the polarization state of the ultra-wideband optical signal after polarization state adjustment output by the third polarization controller; An optical fiber ring is configured to generate a stimulated Brillouin effect between the polarization-adjusted pump light output by the fourth polarization controller and the polarization-adjusted ultra-wideband optical signal output by the third polarization controller in the optical fiber ring, thereby generating an ultra-narrowband swept-frequency light within a wide frequency band; The optical circulator is configured to introduce the polarization-adjusted pump light output by the fourth polarization controller and the ultra-wideband optical signal output by the third polarization controller into the optical fiber ring, and to export the backscattered light generated by the stimulated Brillouin effect in the optical fiber ring, that is, to export the ultra-narrowband swept light, so as to realize ultra-narrowband filtering of the ultra-wideband optical signal.

8. The ultra-wideband light generating device based on a microwave photon filter according to claim 7, characterized in that: The optical fiber ring is made of bismuth-doped optical fiber or chalcogenide glass optical fiber.

9. A method for generating ultra-wideband light based on a microwave photon filter, characterized in that: Using the ultra-wideband light generating device based on a microwave photon filter as described in any one of claims 1 to 8, the method comprises the following steps: (1) In the broadband light generating unit, a frequency-stabilized single-frequency laser generates single-wavelength frequency-stabilized linearly polarized light as signal light, and the polarization state of the signal light is adjusted by a first polarization controller; (2) In the broadband light generating unit, under the control of the frequency stabilization & wavelength tuning control module, the tunable DFB laser generates a single-wavelength frequency-stabilized linearly polarized light having a wavelength deviation from the output light of the frequency-stabilized single-frequency laser as the local oscillator light, and the polarization state of the local oscillator light is adjusted by the second polarization controller; the polarization state of the local oscillator light after the polarization state is adjusted matches the polarization state of the signal light after the polarization state is adjusted; (3) In the broadband light generating unit, the signal light and the local oscillator light with matched polarization states are heterodyned in the optical mixer to generate an ultra-broadband optical signal, which then enters the actively tuned narrowband filtering unit through the optical isolator. (4) In the actively tuned narrowband filter unit, the ultra-wideband optical signal generated in step (3) is polarized by a third polarization controller, and the third polarization controller outputs the ultra-wideband optical signal after polarization state adjustment; (5) In the actively tuned narrowband filter unit, the swept frequency pump light with continuously changing wavelength generated by the tunable laser is amplified in a power-configurable manner by the optical amplifier, and then the polarization state is adjusted by the fourth polarization controller, and the polarization state of the pump light after the polarization state adjustment output by the fourth polarization controller matches the polarization state of the ultra-wideband optical signal after the polarization state adjustment output by the third polarization controller; (6) In the actively tuned narrowband filter unit, the swept pump light after polarization state adjustment output by the fourth polarization controller and the ultra-wideband optical signal after polarization state adjustment output by the third polarization controller enter the optical fiber ring through the optical circulator to produce stimulated Brillouin effect, thereby generating an ultra-narrowband swept light of the MHz order with a center frequency that continuously changes within a wide bandwidth. The ultra-narrowband swept light is output through the optical circulator, thereby realizing the generation of actively tunable ultra-narrow filter bandwidth and ultra-wideband signal light.

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