Near-infrared wide-spectrum pulse light source generator

Abstract

The invention discloses a near-infrared wide-spectrum pulse light source generator, belongs to the technical field of laser light source manufacturing, and aims to solve the problems of complex system structure and high cost due to the fact that a supercontinuum laser generates supercontinuum through multi-stage power amplification in the prior art. The device is composed of a first semiconductor pump laser, a first wavelength division multiplexer, a first gain optical fiber, a first filter, a first dispersion compensation optical fiber, a first high-nonlinearity optical fiber, a first isolator, an optical fiber coupler, a second semiconductor pump laser, a second wavelength division multiplexer, a second gain optical fiber, a second filter, a second dispersion compensation optical fiber, a second high-nonlinearity optical fiber and a second isolator. According to the invention, the characteristic of high mode-locked pulse energy of the Mmyshev oscillator is utilized, multi-stage power amplification is not needed, and the super-continuum spectrum can be directly generated, so that the system structure is simplified, and the cost is reduced; the laser light source can be applied to multiple fields of laser sensing, photoelectric countermeasure, remote sensing detection, optical imaging and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to a near-infrared wide-spectrum pulsed light source generator, belonging to the technical field of laser light source manufacturing, which can be applied to laser sensing, photoelectric countermeasures, remote sensing detection, optical imaging and other fields. BACKGROUND

[0002] Wide-spectrum pulsed lasers are a class of optical light sources with extremely wide spectral bandwidth, which have important application value in the fields of optical fiber communication, optical imaging, photoelectric countermeasures, laser sensing and spectroscopy. The generation of traditional wide-spectrum pulses usually relies on high-power ultra-short pulsed lasers through high nonlinear optical fibers or photonic crystal fibers to achieve nonlinear effects such as self-phase modulation, four-wave mixing and stimulated Raman scattering, thereby obtaining wide-band spectrum. However, there are several problems in the practical application of this method. First, to obtain high-quality supercontinuum spectrum, the pump light usually requires a high-power, narrow-linewidth and mode-locked laser source, which has high system cost and complex structure. Second, traditional mode-locked lasers are sensitive to environmental changes, such as temperature, vibration and polarization state changes, which can cause pulse instability, thereby causing spectral fluctuations and output power reduction. In addition, most systems require external seed or additional amplifiers to obtain pulses with sufficient energy, which further increases the system complexity.

[0003] Chinese patent publication No. "CN119651328A" is entitled "All-fiber flat ultraviolet-to-mid-infrared supercontinuum laser based on a single seed source". The device structure is as follows: it includes a seed laser, two-stage ytterbium-doped erbium fiber amplifiers, a high nonlinear fiber NL-1550, a large-mode-area ytterbium-doped erbium fiber amplifier, a large-mode-area ytterbium-doped fiber amplifier, a photonic crystal fiber, and a passive fluorine fiber connected in sequence. The seed laser outputs a 1.55 μm seed pulse laser, and the final output spectrum ranges from 370 to 4500 nm, covering the ultraviolet-to-mid-infrared band of the supercontinuum laser. The present application adopts an all-fiber structure, has high stability and portability, reduces the loss and system complexity in the process of light transmission; through a single seed source, double-wavelength pumping is realized, and through a multi-stage amplification structure and a multi-stage nonlinear medium structure, super-flat spectrum output covering the ultraviolet to the mid-infrared is realized.

[0004] However, the super-wide spectrum generated by this structure is not directly output from the oscillator, but the pulse laser output from the oscillator is amplified multiple times to improve the pulse energy, and then input to the high nonlinear fiber (different high nonlinear fibers are used for ultraviolet, near-infrared and mid-infrared) to realize the output of super-wide spectrum laser pulses through various nonlinear effects. Therefore, this laser generates supercontinuum spectrum through multi-stage power amplification, which has the problems of complex structure and high cost. SUMMARY

[0005] The present application discloses a near-infrared wide-spectrum pulse light source generator, which is characterized by simple structure, low cost and high stability.

[0006] The present application adopts the following technical scheme:

[0007] The near-infrared wide-spectrum pulse light source generator is composed of a first semiconductor pump laser, a first wavelength division multiplexer, a first gain optical fiber, a first filter, a first dispersion compensation optical fiber, a first high nonlinear optical fiber, a first isolator, a fiber coupler, a second semiconductor pump laser, a second wavelength division multiplexer, a second gain optical fiber, a second filter, a second dispersion compensation optical fiber, a second high nonlinear optical fiber and a second isolator.

[0008] The first semiconductor pump laser is connected with port A of the first wavelength division multiplexer, port C of the first wavelength division multiplexer is connected with the first gain optical fiber, the first gain optical fiber is connected with the first filter, the first filter is connected with the first dispersion compensation optical fiber, the first dispersion compensation optical fiber is connected with the first high nonlinear optical fiber, the first high nonlinear optical fiber is connected with the first isolator, the first isolator is connected with port D of the fiber coupler, port E of the fiber coupler is connected with port E of the second wavelength division multiplexer, and port F of the fiber coupler is a pulse laser output port; the second semiconductor pump laser is connected with port H of the second wavelength division multiplexer, port I of the second wavelength division multiplexer is connected with the second gain optical fiber, the second gain optical fiber is connected with the second filter, the second filter is connected with the second dispersion compensation optical fiber, the second dispersion compensation optical fiber is connected with the second high nonlinear optical fiber, the second high nonlinear optical fiber is connected with the second isolator, and the second isolator is connected with port B of the first wavelength division multiplexer, thereby forming a ring cavity.

[0009] The first conductor pump laser is connected with the A port of the first wavelength division multiplexer to transmit pump light, the second conductor pump laser is connected with the H port of the second wavelength division multiplexer to transmit pump light, then the pump power is injected into the first gain optical fiber and the second gain optical fiber through the C port of the first wavelength division multiplexer and the I port of the second wavelength division multiplexer, the two gain optical fibers generate self-phase modulation light signals respectively, the two self-phase modulation light signals pass through the first filter and the second filter respectively to narrow the spectrum, the filtered light signals pass through the first dispersion compensation optical fiber and the second dispersion compensation optical fiber respectively to be shaped by the compensated dispersion coefficient, then pass through the first high nonlinear optical fiber and the second high nonlinear optical fiber respectively to be spectrum widened by the high nonlinear coefficient, the first isolator and the second isolator are the same in direction and are counterclockwise or clockwise to ensure the unidirectional operation of the laser signal in the ring cavity, the spectrum after being widened passes through the first isolator and enters the fiber coupler to be power split, 90% of the light signal enters the G port of the second wavelength division multiplexer through the E port of the fiber coupler, 10% of the energy is output through the F port of the fiber coupler, and the light signal after being widened by the second high nonlinear optical fiber passes through the second isolator and is connected to the B port of the first wavelength division multiplexer, the light signal continuously experiences power amplification, filtering, shaping, spectrum widening and power amplification in the ring cavity, and finally forms a stable wide-spectrum pulse laser signal output.

[0010] The present application has the advantages that: the all-fiber structure near-infrared wide-spectrum pulse light source directly generates high-power supercontinuum spectrum by using the self-starting mode-locking characteristics of the Mamyshev oscillator, without the need for an external mode-locked laser or a seed light source, thereby simplifying the system structure and reducing the cost; meanwhile, the all-polarization-maintaining fiber design or the non-all-polarization-maintaining fiber structure with polarization control optimization is adopted, the system has strong stability to temperature, vibration and polarization changes, and long-term stable operation can be realized; by adjusting the filter parameters, pump power and nonlinear fiber or dispersion compensation length, the bandwidth, power distribution and center wavelength of the supercontinuum spectrum can be flexibly controlled, wide-spectrum coverage from near-infrared to mid-infrared is realized, and high-power, high-smoothness spectrum output is obtained. Meanwhile, the present application adopts an all-fiber structure, there is no spatial structure component, the loss is low, the performance is stable, and it is easy to integrate with other fiber systems. The present application has low cost, high productization degree, high cost performance, and practical application value in the fields of laser sensing, photoelectric countermeasure, remote sensing detection, optical imaging and the like. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a near-infrared wide-spectrum pulse light source generator structure diagram of the present application.

[0012] Figure 2 It is a time-domain diagram for realizing super-wide-spectrum laser pulse output of the present application.

[0013] Figure 3 A spectrum diagram for realizing the super wide spectrum laser pulse output of the present application. DETAILED DESCRIPTION

[0014] The present application will be further described in detail below with reference to the accompanying drawings.

[0015] As Figure 1 shown, a near-infrared wide spectrum pulse light source generator is composed of a first semiconductor pump laser 1, a first wavelength division multiplexer 2, a first gain optical fiber 3, a first filter 4, a first dispersion compensation optical fiber 5, a first high nonlinear optical fiber 6, a first isolator 7, a fiber coupler 8, a second semiconductor pump laser 9, a second wavelength division multiplexer 10, a second gain optical fiber 11, a second filter 12, a second dispersion compensation optical fiber 13, a second high nonlinear optical fiber 14 and a second isolator 15.

[0016] The first semiconductor pump laser 1 is connected with the A port of the first wavelength division multiplexer 2, the C port of the first wavelength division multiplexer 2 is connected with the first gain optical fiber 3, the first gain optical fiber 3 is connected with the first filter 4, the first filter 4 is connected with the first dispersion compensation optical fiber 5, the first dispersion compensation optical fiber 5 is connected with the first high nonlinear optical fiber 6, the first high nonlinear optical fiber 6 is connected with the first isolator 7. The first isolator 7 is connected with the D port of the fiber coupler 8, the E port of the fiber coupler 8 is connected with the G port of the second wavelength division multiplexer 10, the F port of the fiber coupler 8 is the pulse laser output port. The second semiconductor pump laser 9 is connected with the H port of the second wavelength division multiplexer 10, the I port of the second wavelength division multiplexer 10 is connected with the second gain optical fiber 11, the second gain optical fiber 11 is connected with the second filter 12, the second filter 12 is connected with the second dispersion compensation optical fiber 13, the second dispersion compensation optical fiber 13 is connected with the second high nonlinear optical fiber 14, the second high nonlinear optical fiber 14 is connected with the second isolator 15, and the second isolator 15 is connected with the B port of the first wavelength division multiplexer 2. Finally, a ring cavity is formed.

[0017] The first conductor pump laser 1 is connected with the A port of the first wavelength division multiplexer 2, and the second conductor pump laser 9 is connected with the H port of the second wavelength division multiplexer 10, and then the pump power is injected into the first gain fiber 3 and the second gain fiber 11 through the C port of the first wavelength division multiplexer 2 and the I port of the second wavelength division multiplexer 10, the two gain fibers generate self-amplified light signals respectively, the two self-amplified light signals are filtered through the first filter 4 and the second filter 12 respectively, the filtered light signals are shaped through the first dispersion compensation fiber 5 and the second dispersion compensation fiber 13 respectively, the shaped light signals are spectrum widened through the first high nonlinear fiber 6 and the second high nonlinear fiber 14 respectively, the first isolator 7 and the second isolator 15 are the same in direction and are counterclockwise or clockwise, which ensures the unidirectional operation of the laser signal in the ring cavity. After the spectrum widened light signal passes through the first isolator 7, it enters the fiber coupler 8 to split the power, 90% of the light signal enters the G port of the second wavelength division multiplexer 10 through the E port of the fiber coupler 8, and 10% of the energy is output through the F port of the fiber coupler 8. The spectrum widened light signal passing through the second high nonlinear fiber 14 enters the B port of the first wavelength division multiplexer 2 after passing through the second isolator 15. The light signal continuously experiences power amplification, filtering, shaping, spectrum widening and power amplification in the ring cavity, and finally forms a stable wide spectrum pulse laser signal output.

[0018] The first dispersion compensation fiber 5 and the second dispersion compensation fiber 13 in the ring cavity are used to compensate the negative dispersion in the cavity caused by other fibers, so that the net dispersion in the cavity is positive, which can shape the time domain of the light signal in real time and prevent pulse splitting.

[0019] The filtering center wavelength and bandwidth of the first filter 4 and the second filter 12 do not overlap with each other, forming a bias filtering effect. It meets the requirement of the pulse signal generated by the Mamyshev oscillator.

[0020] The first high nonlinear fiber 6 and the second high nonlinear fiber 14 in the ring cavity are used to improve the nonlinear effect in the cavity, so that the spectrum is sufficiently widened, which is used to maintain the normal operation of the Mamyshev oscillator bias filtering effect, and directly output the wide spectrum laser pulse through the coupler F end.

[0021] As shown in Figure 2 , a time domain diagram for realizing an ultra-wide spectrum laser pulse output. When the output power of the first semiconductor pump laser 1 and the second semiconductor pump laser 9 is adjusted to exceed the mode locking threshold power of the ring cavity oscillator, a typical pulse time domain diagram is output from the F end of the fiber coupler 8. In the figure, the abscissa represents time, the unit is μs, and the ordinate represents the normalized intensity of the pulse signal. Figure 2The part of the middle protrusion is the effective pulse signal, and the interval and width of the pulse are determined by the parameters of the resonant cavity.

[0022] As Figure 3 shown in the spectrum diagram for realizing the output of the ultra-wideband spectrum laser pulse, the first gain fiber 3 and the second gain fiber 11 are erbium-doped fibers. By adjusting the lengths of the first dispersion compensation fiber 5 and the second dispersion compensation fiber 13, the lengths of the first high nonlinear fiber 6 and the second high nonlinear fiber 14, and the output powers of the first semiconductor pump laser 1 and the second semiconductor pump laser 9, after stable mode locking, the wideband spectrum laser pulse can be directly output from the F end of the fiber coupler 8, and the result is shown in Figure 3 . Figure 3 The abscissa represents the wavelength of the spectrum, and the unit is nm; the ordinate represents the power density of the spectrum, and the unit is dBm. The width of the spectrum is determined by the output powers of the first semiconductor pump laser 1 and the second semiconductor pump laser 9 and the total nonlinear coefficient in the cavity. The typical output spectrum can be from 1450 nm to 2000 nm, and as the pump power in the cavity increases, the spectrum range can cover 400 nm to 2400 nm at most.

Claims

1. A near-infrared wide-spectrum pulsed light source generator, characterized by, It is by the first semiconductor pump laser (1), the first wavelength division multiplexer (2), the first gain fiber (3), the first filter (4), the first dispersion compensation fiber (5), the first high nonlinear fiber (6), the first isolator (7), fiber coupler (8), the second semiconductor pump laser (9), the second wavelength division multiplexer (10), the second gain fiber (11), the second filter (12), the second dispersion compensation fiber (13), the second high nonlinear fiber (14) and the second isolator (15) is composed of; The first semiconductor pump laser (1) is connected with the A port of the first wavelength division multiplexer (2), the C port of the first wavelength division multiplexer (2) is connected with the first gain fiber (3), the first gain fiber (3) is connected with the first filter (4), the first filter (4) is connected with the first dispersion compensation fiber (5), the first dispersion compensation fiber (5) is connected with the first high nonlinear fiber (6), the first high nonlinear fiber (6) is connected with the first isolator (7), the first isolator (7) is connected with the D port of the fiber coupler (8), the E port of the fiber coupler (8) is connected with the G port of the second wavelength division multiplexer (10), the F port of the fiber coupler (8) is the pulse laser output port, the second semiconductor pump laser (9) is connected with the H port of the second wavelength division multiplexer (10), the I port of the second wavelength division multiplexer (10) is connected with the second gain fiber (11), the second gain fiber (11) is connected with the second filter (12), the second filter (12) is connected with the second dispersion compensation fiber (13), the second dispersion compensation fiber (13) is connected with the second high nonlinear fiber (14), the second high nonlinear fiber (14) is connected with the second isolator (15), the second isolator (15) is connected with the B port of the first wavelength division multiplexer (2), finally forms a ring cavity.

2. The near-infrared wide-spectrum pulsed light source generator according to claim 1, wherein, The first conductor pump laser (1) is connected with the A port of the first wavelength division multiplexer (2) to transmit pump light, the second conductor pump laser (9) is connected with the H port of the second wavelength division multiplexer (10) to transmit pump light, then the pump power is injected into the first gain optical fiber (3) and the second gain optical fiber (11) through the C port of the first wavelength division multiplexer (2) and the I port of the second wavelength division multiplexer (10), the two gain optical fibers generate self-phase modulation light signals respectively, the self-phase modulation light signals pass through the first filter (4) and the second filter (12) to narrow the spectrum, then pass through the first dispersion compensation optical fiber (5) and the second dispersion compensation optical fiber (13) to shape the spectrum by using the compensated dispersion coefficient, then pass through the first high nonlinear optical fiber (6) and the second high nonlinear optical fiber (14) to broaden the spectrum by using the high nonlinear coefficient, the first isolator (7) and the second isolator (15) pass through in the same direction, that is, counterclockwise or clockwise, to ensure the unidirectional operation of the laser signal in the ring cavity, the broadened spectrum passes through the first isolator (7) and enters the fiber coupler (8) to split the power, 90% of the light signal enters the G port of the second wavelength division multiplexer (10) through the E port of the fiber coupler (8), 10% of the energy is output through the F port of the fiber coupler (8), and the light signal continuously experiences power amplification, filtering, shaping, spectrum broadening and power amplification in the ring cavity, and finally forms a stable wide-spectrum pulse laser signal output.

3. The near-infrared wide-spectrum pulsed light source generator according to claim 1, wherein, The first dispersion compensation optical fiber (5) and the second dispersion compensation optical fiber (13) in the ring cavity are used to compensate the negative dispersion in the cavity caused by other optical fibers, so that the net dispersion in the cavity is positive, and the shaping of the time domain of the light signal can be performed in real time to prevent pulse splitting.

4. The near-infrared wide-spectrum pulsed light source generator according to claim 1, wherein, The filtering center wavelength and bandwidth of the first filter (4) and the second filter (12) do not overlap with each other, forming a bias filtering effect, which meets the requirement of the Mamyshev oscillator for generating a pulse signal.

5. The near-infrared wide-spectrum pulsed optical source generator according to claim 1, wherein The first high nonlinear optical fiber (6) and the second high nonlinear optical fiber (14) in the ring cavity are used to improve the nonlinear effect in the cavity, so that the spectrum is sufficiently broadened, the normal operation of the Mamyshev oscillator bias filtering effect is maintained, and the wide-spectrum laser pulse is directly output through the F port of the coupler (8).

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