CN101272031A - A self-seed superradiation optical fiber amplification method and amplification device - Google Patents

Abstract

The invention relates to a self-seed super-radiation optical fiber amplification method and device, which is characterized in that: the fiber output end of the super-radiation laser light source adopts anti-reflection treatment, and the other end is added with a total reflection element, a band-pass filter, an optical modulator, A reflective feedback system composed of at least one element with optical characteristic modulation characteristics in the polarizer, so that the superradiant light emitted by the pump light source passes through the reflective feedback system to generate a laser seed signal, and re-enters the optical fiber for amplification . In the present invention, a reflection feedback system with specific reflection characteristics is added to one end of the super-radiation optical fiber, so that the required components are selected in the super-radiation fluorescent beam to form a laser signal seed, and then amplified through the super-radiation optical fiber, and the output has the required characteristics In this way, the reflection feedback system with different reflection characteristics can be used to control the output laser characteristics of the superradiant fiber.

Description

A self-seed superradiation optical fiber amplification method and amplification device

technical field

The invention relates to a self-seed super-radiation optical fiber amplification method and an amplification device.

Background technique

The concept of a superradiant laser is proposed in the World Intellectual Property Organization patent WO200035058 and the European patent EP817335. Superradiant laser is also called amplified spontaneous emission laser, which is the laser output formed by the amplified spontaneous emission transition under pumping light pumping. The difference between it and laser output is that due to the absence of laser oscillation and fine longitudinal mode structure, the output spectrum is continuous, and even the spectral density of the output power is flat in a certain spectral range. The beam quality of ordinary super-radiant laser is poor, but the beam quality of super-radiant fiber laser is guaranteed because the laser is limited in the core of a certain size. However, the existing superradiant fiber lasers have certain limitations in many aspects such as efficiency and output linewidth.

In the prior art, although the European patent EP1079482 proposed a method for realizing high-efficiency, high-power, wide-spectrum superradiant laser, these patents all focus on achieving a wide flat spectral output (generally greater than 30nm), and use broadband reflection Mirror and gain flattening filter, when this method is applied to narrow spectral line width output, the filtering efficiency is too low to be directly applied. U.S. Patent US6424762 proposes a method of using a dense wavelength division multiplexer (DWDM) to realize a narrower spectrum superradiant laser (the typical value of the spectral width is 50-200GHz, that is, 0.4-1.6nm), but it is necessary to use this method to achieve a narrower spectrum (0.1nm or so) superradiant laser output is impossible. And in principle, this method is to use dense wavelength division multiplexers to guide light of other wavelengths into other optical fibers, and use high-attenuation optical fibers to attenuate it to a small level, and the structure is much more complicated. In addition, under a certain fiber structure, fiber length, doping concentration and pump wavelength, the patent can also be used to control the output spectral width by adjusting the pump energy, but the output power will be limited when a narrow spectral characteristic is required. Larger restrictions.

The patent WO2003029858 of the World Intellectual Property Organization proposes a method of externally modulating a superradiant fiber laser and then performing fiber amplification. However, this structure is complex, the efficiency is low, and the cost is much higher. European patent EP806821 proposes a method of inserting a polarizer somewhere in the middle of the fiber of super-radiant fiber laser to achieve linearly polarized laser output, but this method is complicated to operate, not easy to implement, and it is difficult to obtain high-power super-radiant laser output.

To sum up, there is currently no method to achieve superradiant laser output with a flat spectral density output around 0.1nm, nor is there a method to achieve pulsed, linearly polarized high-efficiency superradiant laser output.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a self-seed superradiation optical fiber amplification method and amplification device with a wide range of applications and multiple output characteristics.

In order to realize the above-mentioned invention object, the present invention adopts the following technical solutions: a self-seed super-radiation optical fiber amplification method, which is characterized in that: the optical fiber output end of the super-radiation laser light source adopts anti-reflection treatment, and the other end is added with a total reflection element and a band A reflective feedback system composed of at least one element with optical characteristic modulation characteristics among pass filter, optical modulator, and polarizer, so that the superradiant light emitted by the pump light source passes through the reflective feedback system to generate a laser seed signal, and regenerates into the optical fiber for amplification.

The reflective feedback system includes a total reflection element and a band-pass filter, so that the light incident into the optical fiber through the reflective feedback system is only light with a required narrow line width.

The reflection feedback system includes a total reflection element and a light modulator, so that the light incident into the optical fiber through the reflection feedback system is only the light of the required specific pulse sequence.

The reflection feedback system includes a total reflection element and a polarizer, and the optical fiber adopts a polarization-maintaining laser fiber, so that the light incident into the optical fiber through the reflection feedback system is only the required linearly polarized light.

The reflective feedback system includes a total reflection element, an optical modulator and a polarizer, and the optical fiber adopts a polarization-maintaining laser fiber, so that the light incident into the optical fiber through the reflective feedback system has only the required linear polarization and Light of a specific pulse sequence.

The reflective feedback system includes a total reflection element, a bandpass filter and a polarizer, and the optical fiber adopts a polarization-maintaining laser fiber, so that the light incident into the optical fiber through the reflective feedback system has only the required narrow line broad and linearly polarized light.

The reflective feedback system includes a total reflection element, a band-pass filter and a light modulator, so that the light incident into the optical fiber through the reflective feedback system only has the required narrow line width and specific pulse sequence.

The reflective feedback system includes a total reflection element, an optical modulator, a polarizer and a bandpass filter, and the optical fiber adopts a polarization-maintaining laser fiber, so that the light incident into the optical fiber through the reflective feedback system has only Light with narrow linewidth, linear polarization and specific pulse sequence required.

A kind of device that realizes above-mentioned self-seed superradiation optical fiber amplification method, it is characterized in that: at least one of total reflection element and band-pass filter, optical modulator, polarizer has light A reflective feedback system composed of elements with characteristic modulation features, through which the light generated by the reflective feedback system re-enters the optical fiber.

The total reflection element of the reflection feedback system is one of a fiber grating with certain spectrum reflection characteristics, a separate total reflection mirror and a fiber optic total reflection mirror.

The band-pass filter of the reflection feedback system is one of an interference filter, a fiber filter and a fiber grating with a specific spectral bandwidth.

The optical modulator of the reflective feedback system is one of an ordinary discrete laser modulator and a laser modulator coupled with optical fibers at both ends.

The polarizer of the reflective feedback system is one of single polarization optical fiber and discrete polarizer.

Because the present invention adopts the above technical scheme, it has the following advantages: 1. The present invention utilizes a reflection feedback system with specific reflection characteristics added at one end of the super-radiation optical fiber, so that required components can be selected in the super-radiation fluorescent beam to form a super-radiation fiber. The seeds of the fiber laser source are irradiated, and then amplified by the super-radiation fiber, and the laser with the required characteristics is output, so as to realize the control of the output laser characteristics of the super-radiation fiber. 2. In the present invention, a total reflection element is set in the reflection feedback system to realize the reflection and re-injection of the self-seed; a band-pass filter with a certain bandwidth is set in a certain wavelength range, and the output spectral line width and range of the superradiation laser can be controlled At the same time, because the band-pass filter directly selects and cuts the frequency of the laser seed signal before it is fed back into the amplification stage of the fiber again, it avoids the possibility of frequency-cutting the output laser in order to obtain a superradiant laser with a narrower spectrum A large amount of power loss is caused, the structure is relatively simple, and it is easy to realize all-fiber. 3. The present invention arranges an optical modulator with certain characteristics in the reflective feedback system, which can realize the pulsed superradiation laser light source, and controls its output pulse width and pulse repetition frequency; a polarizer with a single polarization optical fiber is provided, and Using polarization-maintaining fiber as a gain medium can control the output polarization state of superradiant laser, which is beneficial to improve the efficiency of fiber laser light source under the premise of adjustable output characteristics. The method and the device of the invention are easy to control, and can guarantee higher power output under the premise of requiring certain output spectral line width, pulse width, pulse repetition frequency and output polarization state.

Description of drawings

Fig. 1 is a structural representation of the present invention

Fig. 2 is a structural schematic diagram of Embodiment 1 of the present invention

Fig. 3 is the structural representation of embodiment 2 of the present invention

Fig. 4 is a structural schematic diagram of Embodiment 3 of the present invention

Fig. 5 is a structural schematic diagram of Embodiment 4 of the present invention

Detailed ways

As shown in Figure 1, the method of the present invention is that a reflection feedback system 2 is set at one end of the optical fiber 1 of the superradiation laser source, so that the amplified fluorescent light beam output from the superradiation laser source performs spectrum, pulse characteristics and The modulation of the polarization state forms a laser seed signal, which is then injected back into the same optical fiber 1 for amplification to output laser light that meets specific requirements. The present invention can use the reflection feedback system 2 with different reflection characteristics to form different laser seed signals, so as to realize the control of various characteristics such as line width, pulse width and polarization state of the output laser of the superradiation fiber.

The reflection feedback system 2 of the present invention includes a total reflection element 21 , and at least one of a bandpass filter 22 , a light modulator 23 and a polarizer 24 . Setting the total reflection element 21 in the reflection feedback system 2 can realize reflection and re-injection from the seed; setting a band-pass filter 22 with a certain bandwidth in a certain wavelength range in the reflection feedback system 2 can control the output of the super-radiation laser Spectral line width and range, at the same time because the band-pass filter 22 directly carries out frequency selection and cut-off frequency to the laser seed signal before the amplification stage of re-injection into the optical fiber through feedback, thus avoiding the need to Output laser for frequency interception may cause a large amount of power loss, the structure is relatively simple, and it is easy to realize all-fiber. A light modulator 23 with certain characteristics is set in the reflective feedback system 2 to realize a pulsed superradiative laser light source and control its output pulse width and pulse repetition frequency. A polarizer 24 with a single polarization fiber is set in the reflection feedback system 2, and the polarization maintaining fiber is used as a gain medium, so that the output polarization state of the superradiant laser can be controlled.

The following are some specific embodiments of the device of the present invention.

Example 1: All-fiber narrow-linewidth superradiant laser source

As shown in Figure 2, the output end of the optical fiber 1 of the all-fiber narrow-linewidth superradiation laser source in this embodiment adopts anti-reflection measures, and an optical fiber filter 3 and an optical fiber total reflection mirror 4 are sequentially welded at the other end, wherein the optical fiber filter 3 and the fiber optic total reflection mirror 4 form a reflection feedback system 2 with specific reflection characteristics. In this way, in the superradiant fluorescent beam, only the light with the required narrow linewidth can be reflected and fed back to the optical fiber 1 of the superradiant laser source for amplification, and the required narrow linewidth laser beam is output.

Example 2: All-fiber narrow-linewidth pulsed superradiant fiber laser

As shown in Figure 3, the output end of the optical fiber 1 of the all-fiber narrow-linewidth pulsed superradiation laser source in this embodiment adopts anti-reflection measures, and the other end is sequentially fused with a pigtail-coupled acousto-optic modulator 5 and an optical fiber with a narrower linewidth. The grating 6, wherein the pigtail-coupled acousto-optic modulator 5 and the fiber grating 6 form a reflection feedback system 2 with specific reflection characteristics. In this way, only the required narrow linewidth and specific pulse sequence light energy in the superradiant fluorescent beam is reflected and fed back to the optical fiber 1 of the superradiant laser source for amplification, and the required narrow linewidth pulse laser beam is output.

Example 3: All-fiber narrow-linewidth, linearly polarized pulsed superradiant fiber laser

As shown in Figure 4, the output end of the optical fiber 1 of the all-fiber narrow-linewidth and linearly polarized pulsed superradiation laser source in this embodiment adopts anti-reflection measures, and the other end is sequentially fused with a single-polarized optical fiber 7 and a pigtail coupled acousto-optic modulation 5 and fiber grating 6 with a narrower line width, wherein the single polarization fiber 7, the pigtail coupled acousto-optic optical modulator 5 and the fiber grating 6 with a narrower line width constitute a reflective feedback system 2 with specific reflection characteristics. In this way, only the required narrow linewidth, linear polarization and light energy of specific pulse sequence in the superradiant fluorescent beam are reflected and fed back to the optical fiber 1 of the superradiant laser source for amplification, and the output required narrow linewidth, line Polarized pulsed laser beam. The optical fiber 1 of the superradiant laser source in this embodiment must be a polarization-maintaining laser optical fiber.

Example 4: Narrow-linewidth, linearly polarized pulsed superradiant fiber laser with discrete components

As shown in Figure 5, the output end of the optical fiber 1 of the narrow-linewidth, linearly polarized pulsed superradiation laser light source of the discrete components of the present embodiment adopts anti-reflection measures, and a single polarization optical fiber 7 is welded on the other end, and passes through the collimation coupling system 8 collimation, ordinary acousto-optic modulator 9 modulation, Fabry interference filter 10 filtering and total reflection mirror 11 reflection, return and re-inject into the fiber, in which single polarization fiber 7, collimation coupling system 8 collimation, ordinary acousto-optic The modulator 9, the Fabry interference filter 10 and the total reflection mirror 11 form a reflection feedback system 2 with specific reflection characteristics. In this way, only the required narrow linewidth, linear polarization and light energy of specific pulse sequence in the superradiant fluorescent beam are reflected and fed back to the optical fiber 1 of the superradiant laser source for amplification, and the output required narrow linewidth, line Polarized pulsed laser beam. The superradiance fiber used in the superradiance laser light source in this embodiment must be a polarization-maintaining laser fiber; the Fabry interference filter 10 must be placed obliquely.

Above-mentioned each embodiment is only the embodiment that enumerates for illustrating the present invention, and the present invention is not limited thereto, and the increase and decrease carried out according to the technical solution of the present invention and the improvement of replacement parts should not be excluded outside the protection scope of the present invention.

Claims (13)

1. A self-seed super-radiation optical fiber amplification method is characterized in that: the optical fiber output end of the super-radiation laser light source adopts anti-reflection processing, and the other end is added by a total reflection element and a band-pass filter, an optical modulator, and a polarizer A reflective feedback system composed of at least one element with optical characteristic modulation features, so that the superradiant light emitted by the pump light source passes through the reflective feedback system to generate a laser seed signal, and re-enters the optical fiber for amplification. 2. a kind of method for amplifying from seed superradiation fiber as claimed in claim 1, is characterized in that: described reflection feedback system comprises total reflection element and band-pass filter, makes incident to described reflection feedback system through described reflection feedback system The light in the fiber has only the required narrow linewidth. 3. a kind of method for amplifying from seed superradiation fiber as claimed in claim 1, is characterized in that: described reflective feedback system comprises total reflection element and light modulator, makes incident in described optical fiber through described reflective feedback system The light is only the light required for the specific pulse sequence. 4. a kind of method for amplifying from seed superradiation fiber as claimed in claim 1, is characterized in that: described reflection feedback system comprises total reflection element and polarizer, and described optical fiber adopts the laser fiber of polarization maintaining, makes through The light incident into the optical fiber by the reflective feedback system is only the required linearly polarized light. 5. a kind of method for amplifying from seed superradiation fiber as claimed in claim 1, is characterized in that: described reflective feedback system comprises total reflection element, light modulator and polarizer, and described optical fiber adopts the laser light of polarization maintaining An optical fiber, so that the light incident into the optical fiber through the reflective feedback system only has the required linear polarization and the light of a specific pulse sequence. 6. a kind of method for amplifying from seed superradiance fiber as claimed in claim 1, is characterized in that: described reflective feedback system comprises total reflection element, band-pass filter and polarizer, and described optical fiber adopts polarization-maintaining The laser optical fiber makes the light incident into the optical fiber through the reflective feedback system only have the required narrow line width and linearly polarized light. 7. a kind of method for amplifying from seed superradiation fiber as claimed in claim 1, is characterized in that: described reflection feedback system comprises total reflection element, band-pass filter and light modulator, makes incident through described reflection feedback system The light into the fiber has only the required narrow linewidth and specific pulse sequence. 8. A kind of method for amplifying from seed superradiant fiber as claimed in claim 1, is characterized in that: described reflective feedback system comprises total reflection element, optical modulator, polarizer and band-pass filter, and described optical fiber A polarization-maintaining laser fiber is used to make the light incident into the fiber through the reflection feedback system only have the required narrow line width, linear polarization and specific pulse sequence. 9. A device for realizing the self-seed super-radiation fiber amplification method as claimed in claims 1 to 8, characterized in that: an optical fiber one end of a super-radiation laser light source is provided with a total reflection element, a band-pass filter, and an optical modulator 1. A reflective feedback system composed of at least one element in the polarizer having optical characteristic modulation features, and the light generated by the reflective feedback system re-enters the optical fiber. 10. A kind of self-seed superradiation optical fiber amplifying device as claimed in claim 9, is characterized in that: the total reflection element of described reflection feedback system is the fiber grating with certain spectral reflection characteristic, discrete total reflection mirror and optical fiber total reflection A type of reflector. 11. A kind of self-seed superradiation optical fiber amplifying device as claimed in claim 9, is characterized in that: the band-pass filter of described reflective feedback system is the interference type filter, fiber filter and fiber grating with specific spectral bandwidth One of. 12. A kind of self-seed superradiation optical fiber amplifying device as claimed in claim 9, is characterized in that: the optical modulator of the reflective feedback system is one of a common discrete laser modulator and a laser modulator coupled with optical fibers at both ends kind. 13. A kind of self-seed superradiation fiber amplifying device as claimed in claim 9, is characterized in that: the polarizer of described reflective feedback system is a kind of in single polarization optical fiber, discrete polarizer.

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