30 results about "Relative intensity noise" patented technology

According to the fiber-optic gyroscope for suppressing the relative intensity noise of the light source based on the double Y waveguides, interference signal light output by the same light source and noise polarization correlation of matched reference light are utilized, fine adjustment is carried out through the design of the two Y waveguides, so that the output intensity of the two Y waveguides is precisely consistent, polarization states are orthogonal, and the relative intensity noise of the gyroscope light source is suppressed; the precision of the gyroscope is improved; multiple polarization beam splitter assembly light paths are specially designed in a gyroscope light path, polarization state orthogonality and equal-light-intensity light splitting and light combination can be achieved, the specific use method of the gyroscope light path design is further provided, fiber-optic gyroscope homologous interference signal light and matched reference light can specifically meet the adjustment requirements, and the method is suitable for popularization and application. The light source relative intensity noise is effectively reduced, and the output signal-to-noise ratio is improved. The device is simple in design structure, low in implementation difficulty, capable of being finely adjusted, high in adaptability, good in noise suppression effect, suitable for single-axis and multi-axis fiber-optic gyroscopes and also suitable for other fiber-optic sensors with similar optical path structures.

The present invention discloses an optical transceiver integrated module with relative intensity noise suppression for a fiber optic gyroscope (FOG). The module comprises a pump source module, an erbium-doped fiber, and a receiver module. The pump source module and the receiver module are connected via the erbium-doped fiber. The waveguide wavelength division multiplexer in the pump source module comprises three ports: left-side port 1 is axially coupled to a laser pump source core, left-side port 2 is connected to a first Faraday reflector, and right-side port 3 is connected to a first erbium-doped fiber terminal of the erbium-doped fiber. The second erbium-doped fiber terminal of the erbium-doped fiber in the receiver module is axially coupled to a polarization-maintaining filter isolator. The 50:50 polarization-maintaining waveguide coupler comprises four ports: the other end of the polarization-maintaining filter isolator is connected to input port 1, input port 2 is connected to a detector, output port 1 is connected to a pigtail, and output port 2 is connected to a second Faraday reflector. The optical transceiver integrated module provides a reliable technical approach for the integration and miniaturization of high-precision FOGs, reduces optical path loss, and effectively improves the signal-to-noise ratio.

The optical interferometer comprises: a broadband light source that outputs a first light in a given frequency domain with suppressed relative intensity noise (RIN); a wavelength divider that divides the first light into a first component and a second component with a center wavelength different from the first component and outputs the second component; a first optical path that propagates the first component output from the wavelength divider; a second optical path that propagates the second component output from the wavelength divider; and a wavelength synthesizer that combines the first component propagating in the first optical path and the second component propagating in the second optical path as a second light output.

The invention discloses an all-normal dispersion super-continuum spectrum driven resonant optical gyroscope and a working method thereof, and belongs to the field of optical gyroscopes. The input end of the mode-locked laser ML is connected to a left port of the full-normal dispersion photonic crystal fiber ANDi-PCF, input ports of the full-normal dispersion photonic crystal fiber ANDi-PCF and the photoelectric detector PD are connected to two left ports of the circulator CIR respectively, and a right port of the circulator CIR is connected with a left port of the multifunctional integrated optical chip MIOC. And two ports on the right side of the multifunctional integrated optical chip MIOC are respectively connected with two ports of the waveguide ring resonator WRR. Based on the resonance mode of the full-normal dispersion super-continuum spectrum excitation waveguide ring resonator, the influence of relative intensity noise and shot noise on the gyroscope performance is further reduced by using the broadband and smooth light source spectrum pattern, and finally the angle random walk of the gyroscope is promoted.

The invention provides a double-closed-loop optical accelerometer. The double-closed-loop optical accelerometer comprises a sensing head and a signal processing unit, the signal processing unit comprises a laser LD, a first photoelectric detector, a second photoelectric detector, a trans-impedance amplifier, an A / D conversion circuit, a lock-in amplifier, an FPGA, a cantilever beam phase locking controller, a light source power locking controller, a D / A conversion circuit, a linear amplification circuit and a constant current source circuit. The FPGA is used for generating two sinusoidal signals with the same frequency; on the basis that the cantilever beam is stabilized at a closed-loop working point through electromagnetic force driving, phase locking of the cantilever beam is realized through superposition of electromagnetic force modulation, so that the 1 / f noise of the system is reduced, and the influence of stray light interference is eliminated; in addition, closed-loop locking is carried out on the output power of the light source, and low-frequency fluctuation noise and relative intensity noise caused by light power drifting are reduced. The light emitting power of the light source is locked, and the detection precision of the whole optical acceleration is improved.

The application discloses a fiber-optic gyroscope based on double Y waveguides for suppressing relative intensity noise of a light source, utilizes noise polarization correlation of interference signal light and matching reference light output by the same light source, and precisely adjusts the two Y waveguides to make the output intensity of the two Y waveguides consistent, the polarization states of the two Y waveguides orthogonal, suppresses the relative intensity noise of the gyroscope light source, and improves the gyroscope precision; the application specially designs a plurality of polarization beam splitter component light paths in the gyroscope light path, which is helpful to realize polarization state orthogonal, equal light intensity beam splitting and light combining, and further provides a specific use method of the gyroscope light path design, so that the above adjustment requirements of the same source interference signal light and the matching reference light of the fiber-optic gyroscope can be realized, the relative intensity noise of the light source is effectively reduced, and the output signal-to-noise ratio is improved. The application has the advantages of simple design structure, low implementation difficulty, fine adjustment, strong adaptability, good noise suppression effect, and the like, and is not only suitable for single-axis and multi-axis fiber-optic gyroscopes, but also suitable for fiber-optic sensors with other similar light path structures.

This optical interferometer comprises: a broadband light source that outputs first light for which relative intensity noise (RIN) in a prescribed frequency domain has been suppressed; a wavelength divider that wavelength-divides the first light into a first component and a second component having a different center wavelength from the first component and outputs the components; a first optical path through which the first component output from the wavelength divider propagates; a second optical path through which the second component output from the wavelength divider propagates; and a wavelength combiner that combines the first component that has propagated through the first optical path with the second component that has propagated through the second optical path, and outputs the combined components as second light.

The invention provides a high-power low-intensity-noise semiconductor laser chip and a laser, a lower waveguide layer is arranged above an N-type substrate, two optical limiting layers are arranged above the lower waveguide layer, an active layer is clamped between the two optical limiting layers, a grating layer is arranged on the optical limiting layers, and the grating layer is arranged on the N-type substrate. An upper cladding layer is arranged on the grating layer, and a contact metal layer is arranged on the upper cladding layer; the grating layer is integrated with a lambda / 4 phase shift structure; and the semiconductor laser chip adopts a ridge waveguide structure. Compared with a traditional narrow ridge waveguide DFB laser, the narrow ridge waveguide DFB laser has the advantages that under the short cavity length condition, the output power exceeding hundreds of milliwatts, low relative intensity noise, high side mode rejection ratio and the narrow line width of about hundreds of kHz are achieved, and meanwhile the relaxation oscillation frequency of the GHz level is achieved. The laser chip shows good power linearity and single-mode stability in a lower normal temperature range, and is suitable for the fields of high-speed optical fiber communication, microwave photonics and the like with strict requirements on power and noise performance.

The invention belongs to the technical field of optical gyroscopes, and particularly relates to a chip-level wide-spectrum resonant optical gyroscope based on differential detection and a working method thereof. The working light source ASE is connected with the coupler through the polarizer; the coupler is connected with a photoelectric detector PD I, a photoelectric detector PD II, a straight waveguide PM and an optical echo wall micro resonant cavity. The photoelectric detector PD I and the photoelectric detector PD II output detection signals to the signal processing circuit structure AMSP, the amplitude modulation signal circuit structure AMSP transmits alternating current signals with rotating speed information to the lock-in amplifier LIA, and after the alternating current signals pass through the low-pass filter LPF, high-frequency useless signals are filtered out, so that useful direct-current gyroscope rotating speed signals are output. The invention is used for solving the problems of high modulation frequency and obvious RIN noise when a resonant fiber-optic gyroscope driven by a wide-spectrum light source in the prior art inhibits relative intensity noise.

The invention discloses a method for suppressing relative intensity noise of a closed-loop dual-channel fiber-optic gyroscope. The method comprises the following steps: 1) taking two closed-loop Sagnac interferometers as two channels of a closed-loop fiber-optic gyroscope; one light source is used for driving the two closed-loop Sagnac interferometers, and a square wave bias signal and a step wave signal are applied to each channel at the same time; wherein the step wave signals applied to the two channels are the same, and the square wave bias signals applied to the two channels are opposite in phase; 2) calculating a Sagnac phase phi S detected by the closed-loop fiber-optic gyroscope according to a feedback phase phi F of a first closed loop in the closed-loop fiber-optic gyroscope; and 3) calculating error signals Vr1 and Vr2 of a second closed loop in the closed-loop fiber-optic gyroscope, sending the error signals Vr1 and Vr2 to the integrator for feedback control, and calibrating feedback coefficients GM1 and GM2 of the first closed loop, so that the feedback phases of the two channels are the same, and the phase modulation depths are the same. According to the invention, the sensitivity of the closed-loop fiber-optic gyroscope is greatly improved.

The present application relates to the technical field of semiconductor lasers, and in particular to a method and structure for preparing a high-reliability, low-noise vertical laser. A substrate with a lattice direction of [1 0 0]2-15° offset from [1 1 0] is selected; two arc-shaped grooves are etched on the layer structure of the substrate, an opening is formed between the ends of the two arc-shaped grooves, and the opening direction is along the crystal direction [0 0 1]; the oxidation restriction layer is oxidized, and a circular oxidation hole is formed between the two arc-shaped grooves; a passivation protective film is covered at the opening and the surface of the device; the opening is filled, and a metal ring is connected through the opening position to lead the P-pole current injection point to the peripheral area; an elliptical relief with a short-to-long axis ratio of 1:1-1:2 is etched from the surface passivation layer at the top of the light-emitting area. The opening is designed to face the [0 0 1] lattice direction, and the final oxidation shape of the device is circular, which improves reliability. The surface passivation film is etched into an elliptical relief to reduce relative intensity noise and effectively improve transmission quality.

Systems and methods for reducing relative intensity noise are provided. The system can include a photodetector configured to detect the relative intensity noise of a light source. The system can include a transimpedance amplifier configured to provide a feedback loop with the photodetector to generate a first signal based on the detected relative intensity noise. The system can include a controller configured to actuate the light source based on the first signal to reduce the relative intensity noise. In this manner, the system can reduce the relative intensity noise of a light source for various optical systems, including gyroscopic systems.

This invention discloses a microwave photonic image suppression mixer chip and mixing method. The chip integrates a grating coupler, a 1×2 MMI, two single-input dual-output single-ended push-pull silicon-based carrier depletion modulators, two 2×2 MMIs, and two GeSi balanced photodetectors. This scheme, based on a single dual-parallel modulator structure combined with a balanced detector structure, can achieve both orthogonal intermediate frequency (IF) signal output and image suppression. The system structure is simple and highly stable. It eliminates the need for a narrowband optical bandpass filter, resulting in a large system operating bandwidth. By employing a balanced detector structure, the system's relative intensity noise and RF leakage terms are suppressed, while the output IF term gain is increased, leading to a higher system signal-to-noise ratio.

A method of operating a resonator optical gyroscope includes generating optical signals having broadband frequency range; coupling optical signals into optical resonator (OR) to propagate in first direction and out of OR after optical signals pass through OR in first direction; applying phase modulation to optical signals coupled out of OR to generate phase-modulated optical signals; filtering first portion of phase-modulated optical signals to generate filtered, phase-modulated optical signals; generating first electrical signals indicative of power level of the filtered, phase-modulated optical signals and RIN; coupling second portion of phase-modulated optical signals into OR to propagate in second direction and out of OR after phase-modulated optical signals pass through the OR in second direction; generating second electrical signals indicative of power level of phase-modulated optical signals after passing through OR in second direction; and determining a rotation rate based on the first electrical signals and the second electrical signals.

A method of operating a resonator optical gyroscope includes generating optical signals having broadband frequency range; coupling optical signals into optical resonator (OR) to propagate in first direction and out of OR after optical signals pass through OR in first direction; applying phase modulation to optical signals coupled out of OR to generate phase-modulated optical signals; filtering first portion of phase-modulated optical signals to generate filtered, phase-modulated optical signals; generating first electrical signals indicative of power level of the filtered, phase-modulated optical signals and RIN; coupling second portion of phase-modulated optical signals into OR to propagate in second direction and out of OR after phase-modulated optical signals pass through the OR in second direction; generating second electrical signals indicative of power level of phase-modulated optical signals after passing through OR in second direction; and determining a rotation rate based on the first electrical signals and the second electrical signals.

The invention discloses a dual-polarization fiber-optic gyroscope for realizing sensitivity enhancement and relative intensity noise suppression, which belongs to the technical field of fiber-optic gyroscopes and is characterized in that orthogonal polarized light propagating in a polarization-maintaining fiber ring presents complementary response with equal magnitude and opposite symbols to the same rotating speed through dual-polarization modulation of the gyroscope; sensitivity enhancement is realized by using a difference algorithm; and meanwhile, the same and synchronous relative intensity noise in the two polarization states is effectively suppressed by adopting a noise subtraction method. Light emitted by the light source is processed by the polarizer, the circulator and other devices, dual-polarization modulation is completed in the modulator, sensing is performed in the optical fiber ring, finally, the light is converted into electric signals through the photoelectric detector, and signal processing is achieved in the FPGA. The performance of the gyroscope can be effectively improved, and sensitivity enhancement and relative intensity noise suppression are achieved.

The invention discloses a chip, a chip on carrier, a transmitter and related equipment. The chip comprises a conductive substrate, an insulating layer, a quantum well, a first capacitor electrode, a distributed feedback laser (DFB) electrode and an electro-absorption modulator (EAM) electrode, the insulating layer and the quantum well grow on the conductive substrate, the DFB electrode and the EAM electrode grow on the insulating layer and the quantum well, the first capacitor electrode grows on the insulating layer, and the second capacitor electrode grows on the EAM electrode. And the first capacitor electrode is used for forming a first capacitor with the conductive substrate, so that the capacitor is built in the EML chip, the modulation effect of a high-frequency signal on a DFB region can be better eliminated while the COC structure and process are simplified, and differential driving of lower RIN noise is realized.

The application discloses a microwave photonics system double optical path cancellation optical noise elimination method and device. The method comprises the following steps: receiving a pulse light source signal, and inputting the pulse light source signal into a pre-constructed double optical path; collecting an output signal of the double optical path, and constructing the collected output signal of the double optical path into virtual double-channel data; determining a down-conversion signal from the virtual double-channel data by using a Fast-ICA algorithm, so as to realize elimination of an optical noise signal. The above scheme realizes elimination of optical relative intensity noise in a microwave photonics system, has fast calculation speed, can recover the down-conversion signal to the maximum extent, and improves the sensitivity of the system; and the above method does not need strict consistency of amplitudes and phases of double optical path signals, and the phases of the double optical path signals can be different by an integral multiple of a heavy frequency period, so that the method is more easily realized in engineering.

The invention discloses an underground six-component seismograph based on a double-fiber ring structure. The underground six-component seismograph comprises a shell, a three-component accelerometer and three angular velocimeters, each angular velocity meter comprises a double-four-stage symmetrically wound double-fiber ring, and the three double-fiber rings are respectively fixed on three mutually orthogonal surfaces of the shell and are used for respectively detecting rotation signals in three directions by the three angular velocity meters; the three-component accelerometer is fixed on the shell and is used for measuring translation signals in three directions; the angular velocity meter and the three-component accelerometer are connected with clock signals input by the same external clock source, so that time alignment of measurement signals of the angular velocity meter and the three-component accelerometer is guaranteed. The device can simultaneously measure a translation signal and a rotation signal of object motion, can effectively inhibit relative intensity noise, greatly improves the sensitivity of an angular velocity meter, improves the environmental adaptability of a six-component seismograph during underground work, and reduces the influence of an underground environment.

The invention belongs to the technical field of photoelectric device testing, and particularly discloses a narrow-linewidth laser automatic testing system and method and a program product, and the system comprises a noise linewidth analyzer, a relative intensity noise analyzer, an optical switch module, an adjustable optical attenuator, an optical power meter and a processor. And the working states of the noise line width analyzer, the relative intensity noise analyzer, the optical switch module, the adjustable optical attenuator and the optical power meter are uniformly butted and controlled through the processor. According to the invention, the tedious process of manual optical fiber switching and instrument operation can be thoroughly eliminated, automatic and high-efficiency testing of multiple performance parameters of the narrow-linewidth laser is realized, and through automatic power management and optical path switching, connection uncertainty and power setting errors caused by manual operation are eliminated, and the test efficiency is improved. The method guarantees the consistency and accuracy of the test result, and is suitable for the performance evaluation of the narrow-linewidth laser in the scenes of high-speed optical communication, coherent detection and the like.

The application provides a balanced optical detector assembly for a fiber-optic gyroscope, which comprises a pigtail, a photosensitive diode and a carrier thereof, a signal processing circuit, a packaging shell and a packaging cover; the packaging cover covers the packaging shell; the pigtail is aligned with a photosensitive surface on the photosensitive diode and the carrier thereof after passing through the packaging shell; the photosensitive diode and the carrier thereof and the signal processing circuit are fixed on a mounting surface of the packaging shell; electrical communication is achieved between the photosensitive diode and the carrier thereof and the signal processing circuit and between the signal processing circuit and lead wires of the packaging shell by wire bonding. The application realizes perfect balance of signal light and reference light and effectively reduces relative intensity noise of a light source of the fiber-optic gyroscope.

The invention relates to the technical field of fiber-optic gyroscopes, and discloses a fiber-optic gyroscope noise phase resolving and modulating system so as to improve the precision of the fiber-optic gyroscope. The system comprises an ASE light source, an optical fiber circulator, a first optical fiber coupling beam splitter, a second optical fiber coupling beam splitter, a Y waveguide, an optical fiber ring, a spectrograph and a control host. Wherein the first optical fiber coupling beam splitter and the second optical fiber coupling beam splitter are used for carrying out light intensity superposition on two paths of signal light and reference light which have correlation and both contain relative intensity noise in a spectrograph in an orthogonal mode, so that common terms of the two paths of relative intensity noise can be counteracted, and meanwhile, the relative intensity noise of the two paths of relative intensity noise can be eliminated. The control host intercepts a spectral band with composite constraint of flatness and bandwidth range from spectral data detected by the spectrometer, and calculates the central wavelength of the intercepted band while taking light intensity data integrated by the intercepted band as closed-loop feedback quantity acting on the Y waveguide after gain processing; the scale factor that varies with the drift of the center wavelength is then corrected according to the calculation result of the center wavelength.

The application discloses a kind of multi-path parallel balanced receiving photoelectric detector, belong to broadband fast electric field detection technical field, the photoelectric detector includes by 1 / M (M≥2) polarization beam splitter structure of optical beam splitter, by M group balanced photodiode pair photoelectric detection structure, by M current-voltage conversion structure of transimpedance amplification circuit and 1 / M radio frequency power combining structure.The node of every two photodiodes is connected, to output signal in the form of "current self reduction", the differential current signal of two photodiodes is converted into voltage signal using transimpedance amplifier, as a radio frequency output.M path detection signal is through power divider.The light signal carrying modulation signal is first through optical beam splitting to carry out parallel balanced detection, then power is synthesized by radio frequency, can enhance the saturation optical power tolerance of detector whole, and relative intensity noise in system is inhibited to a certain extent, so signal-to-noise ratio of detection signal can be improved.

This application relates to the technical field of semiconductor lasers, and in particular, to a vertical cavity surface emitting semiconductor laser and its manufacturing method, including a substrate, an N-side electrode, an N-type DBR layer, an N-type confinement layer, an active region, a P-type confinement layer, a P-type DBR layer, a confinement layer, a dielectric filling layer, a surface passivation layer, a P-side electrode, a P-type metal contact, and an ALD layer. A confinement hole is provided on the confinement layer, the material of the confinement layer includes Bi₂Se₃, and the confinement hole is a rotationally asymmetric structure. The bandwidth and relative intensity noise RIN of the laser are greatly improved, so that the laser prepared by the solution of this application can meet the high bandwidth and low noise requirements of a single-channel 100 Gbps link; innovatively use Bi₂Se₃ to manufacture the confinement layer of the VCSEL laser, simplify the preparation process of the VCSEL product, and improve the product bandwidth and process uniformity; innovatively use a rotationally asymmetric morphology to manufacture the confinement layer of the VCSEL laser, and optimize the relative intensity noise performance of the product.

The invention relates to the technical field of semiconductor lasers, in particular to a vertical-cavity surface-emitting semiconductor laser and a manufacturing method thereof.The vertical-cavity surface-emitting semiconductor laser comprises a substrate, an N-face electrode, an N-type DBR layer, an N-type limiting layer, an active region, a P-type limiting layer, a P-type DBR layer, a limiting layer, a medium filling layer, a surface passivation layer, a P-face electrode, a P-type metal contact and an ALD layer; the material of the limiting layer comprises BiSe, and the limiting hole is of a rotary asymmetric structure. The bandwidth and the relative intensity noise RIN of the laser are greatly improved, so that the laser prepared by the scheme of the invention can meet the requirements of high bandwidth and low noise required by a single-channel 100Gbps link; biSe is innovatively used for manufacturing the limiting layer of the VCSEL laser, the preparation process of a VCSEL product is simplified, and the product bandwidth and the process uniformity are improved; a limiting layer of a VCSEL laser is manufactured by innovatively using a rotational asymmetric morphology, and the relative intensity noise performance of a product is optimized.

The invention belongs to the field of optical gyroscopes. The invention particularly relates to a resonant fiber-optic gyroscope driven by a low-noise wide-spectrum light source and a working method of the resonant fiber-optic gyroscope. The input end of the working light source ASE and the input end of the photoelectric detector PD are connected to two left side ports of the coupler C1 respectively, two right side ports of the coupler C1 are connected with left side ports of the single polarization phase modulators SPPM1 and SPPM2 respectively, and right side ports of the single polarization phase modulators SPPM1 and SPPM2 are connected with two ports of the fiber ring resonator FRR respectively. According to the invention, while the loss of the sensing unit is fundamentally reduced by using the reflective optical fiber resonant cavity, the influence of relative intensity noise and shot noise on the performance of the gyroscope is further reduced by using an optical cancellation method, and the signal-to-noise ratio of the gyroscope is finally improved.

A method of operating a resonator optical gyroscope, the method comprising: generating an optical signal having a broadband frequency range; coupling the optical signal into an optical resonator (OR) for propagation in a first direction and coupling the optical signal out of the OR after the optical signal passes through the OR in the first direction; applying phase modulation to the optical signal coupled out of the OR to generate a phase modulated optical signal; filtering a first portion of the phase modulated optical signal to generate a filtered phase modulated optical signal; generating a first electrical signal indicative of a power level and RIN of the filtered phase modulated optical signal; coupling a second portion of the phase modulated optical signal into the OR to propagate in a second direction, and coupling the second portion out of the OR after the phase modulated optical signal passes through the OR in the second direction; generating a second electrical signal indicative of a power level of the phase modulated optical signal after passing through the OR in a second direction; and determining a rotation rate based on the first electrical signal and the second electrical signal.

In a VCSEL device with an asymmetric oxide aperture, the asymmetric oxide aperture has a low symmetry shape or pattern with an order of rotation symmetry of zero. An oxide aperture having such a low symmetry pattern breaks the symmetry to eliminate degenerate modes and instability of polarization, which reduces relative intensity noise (RIN) and root-mean-square (RMS) spectra width. In one embodiment, the low symmetry pattern of the asymmetric oxide aperture may be a partial circle, such as a semi-circle or quarter circle, and the arc angle θ of the partial circle may be reduced to increase the OA control limit.

A high-precision fiber optic gyroscope using a relative intensity noise optical cancellation scheme. It adopts an all-fiber structure and utilizes the correlation between the optical signal at the idle end of the coupler and the relative intensity of the interference signal to perform noise cancellation, thereby improving the accuracy of the fiber optic gyroscope. A relative intensity noise suppression technology for the optical cancellation scheme is proposed to reduce the process difficulty and production cost of realizing the high-precision fiber optic gyroscope.

The application discloses a kind of optical frequency comb receiving system noise digital cancellation methods, specifically related to digital signal processing technical field, by beam splitter, femtosecond laser is divided into signal path and noise reference path and synchronous acquisition. After Fourier transform to two-way data, the effective spectrum is divided into initial frequency band and the projection coefficient of each section is calculated. According to the relative difference of adjacent frequency band projection coefficient, the frequency band division is dynamically adjusted, and the adaptive frequency band is formed. In each adaptive frequency band, the projection of signal path on reference path is subtracted, the noise cancellation is realized, and finally the time domain signal is obtained by spectrum reorganization and inverse transform;The application is synchronous acquisition and dynamic frequency band division by signal path and noise reference path, effectively suppresses light source relative intensity noise, and improves signal quality;Digital processing mode is used, without complex hardware adjustment, to reduce system cost;Through adaptive frequency band division, environmental changes are adapted, and noise cancellation stability is improved.