Integrated device for inhibiting spontaneous radiation fluorescence of optical fiber amplification system

Abstract

The utility model relates to an integrated device for suppressing spontaneous radiation fluorescence of an optical fiber amplification system. The integrated device comprises a double-optical-fiber collimator, a roof prism, a signal light filtering diaphragm and a rectangular prism which are arranged in sequence. The narrow-band signal light filtering diaphragm is reasonable in structural design, residual pump light is utilized, the signal light filtering function is achieved, fluorescence generated in the amplification process is blocked, the signal light passes through the narrow-band signal light filtering diaphragm twice, the isolation requirement of the signal light filtering diaphragm can be lowered, the cost of the signal light filtering diaphragm can be reduced, and the service life of the signal light filtering diaphragm is prolonged. And meanwhile, the number of devices is reduced, the number of welding points and optical path loss are reduced, the reliability is greatly improved, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of laser radar, in particular to an integrated device for suppressing spontaneous radiation fluorescence in an optical fiber amplification system. Background Art

[0002] The pulsed laser fiber amplifier used for laser radar has a higher signal-to-noise ratio, that is, the smaller the noise, the better the detection performance of the laser radar. The noise of the pulsed laser fiber amplifier mainly comes from the fluorescence of the amplified spontaneous radiation. The current pulsed laser fiber amplifier usually uses a continuous light pump source. Due to the gain saturation effect of the gain fiber, the low-power signal light can easily reach the gain saturation state during the amplification process, generating fluorescence that is useless to the laser radar. The amplified fluorescence will cause the gain of the signal light to decrease, making the output performance of the pulsed laser fiber amplifier worse. The usual methods of suppressing fluorescence are: using multi-stage amplification to reduce the fluorescence generated by spontaneous radiation, or adding a filter at the end of the amplifier to filter out the fluorescence. For the residual pump light of the active fiber of the fiber laser, a pump light filter is generally used, so that the pump and signal light devices can separate the pump light for use. The above suppression of fluorescence and the use of residual pump light require the introduction of more devices, and the system is relatively complex, which is not conducive to miniaturization. Summary of the invention

[0003] The utility model aims to overcome the shortcomings of the prior art and provide an integrated device for suppressing spontaneous emission fluorescence in an optical fiber amplification system, so as to solve the problems of signal light filtering and residual pump light utilization.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] An integrated device for suppressing spontaneous fluorescence in an optical fiber amplification system, characterized in that it comprises a dual optical fiber collimator, a roof prism, a signal light filter film and a right-angle prism arranged in sequence;

[0006] The dual-fiber collimator is composed of a dual-fiber head, a lens and a glass sleeve. The dual-fiber head includes a first double-clad optical fiber, a second double-clad optical fiber and a capillary. The cladding of the first double-clad optical fiber is used to transmit pump light, and the core is used to transmit signal light; the cladding of the second double-clad optical fiber is used to transmit pump light, and the core is used to transmit signal light; the lens is used for collimating and coupling the pump light and the signal light through the first double-clad optical fiber and the second double-clad optical fiber, and the glass sleeve is used to fix the dual-fiber head and the lens;

[0007] The flat end of the roof prism is coated with a film that is highly reflective of pump light and a film that increases transmittance of signal light, and is used to reflect the pump light collimated and output by the first double-clad optical fiber and the lens back to the lens and couple it to the cladding of the second double-clad optical fiber, and to couple the signal light output by the second double-clad optical fiber core and the lens to the signal light filter film and the right-angle prism group, and couple the signal light reflected by the right-angle prism to the core of the first double-clad optical fiber;

[0008] The signal light filter film is coated with a narrow-band filter film, so that the signal light passes through and the fluorescence is reflected outside the signal light path;

[0009] The right-angle surface of the right-angle prism is coated with a high-reflection film for signal light, which is used to reflect the signal light.

[0010] Furthermore, the angle a of the ridge end of the roof prism is 3.7 degrees.

[0011] Furthermore, the signal light filter membrane is tilted at an angle greater than 0 degrees.

[0012] Compared with the prior art, the utility model has the following effects: reasonable structural design, realizing the utilization of residual pump light, and realizing the signal light filtering function, blocking the fluorescence generated in the amplification process, and the signal light passes through the narrow-band signal light filter membrane twice, which can reduce the isolation requirement of the signal light filter membrane, which is beneficial to reducing the cost of the signal light filter membrane, and at the same time reduces the number of components, the number of welding points and the optical path loss, greatly improving the reliability and reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention is further described in detail below with reference to the accompanying drawings and specific implementations:

[0014] Figure 1 It is a schematic diagram of the structure of the first embodiment of the utility model;

[0015] Figure 2 It is a schematic diagram of the structure of the dual-fiber collimator in the first embodiment of the utility model;

[0016] Figure 3 This is a schematic diagram of the angle of the roof prism in the first embodiment of the utility model;

[0017] Figure 4 It is a schematic diagram of the structure of the second embodiment of the utility model;

[0018] Wherein: 11-dual fiber collimator; 12-roof prism; 13-signal light filter film; 14-right angle prism;

[0019] 111-dual optical fiber head; 112-glass sleeve; 113-lens;

[0020] 1111 - first double-clad optical fiber; 1112 - second double-clad optical fiber; 1113 - capillary tube. DETAILED DESCRIPTION Example

[0021] like Figures 1 to 3 As shown, the utility model is an integrated device for suppressing spontaneous emission fluorescence in an optical fiber amplification system, comprising a dual optical fiber line collimator 11, a roof prism 12, a signal light filter film 13 and a right angle prism 14 which are arranged in sequence.

[0022] The dual-fiber collimator 11 is composed of a dual-fiber head 111, a glass sleeve 112, and a lens 113. The glass sleeve 112 is used to fix the dual-fiber head 111 and the lens 113. The dual-fiber head 111 is composed of a first double-clad fiber 1111, a second double-clad fiber 1112, and a capillary 1113. The first double-clad fiber 1111 is fused to the second-stage double-clad active fiber of the optical amplifier, and the second double-clad fiber 1112 is fused to the first-stage double-clad active fiber of the optical amplifier. The cladding of the first double-clad fiber 1111 is used to transmit pump light, and the core is used to transmit signal light; the cladding of the second double-clad fiber 1112 is used to transmit pump light, and the core is used to transmit signal light; the lens 113 is used for collimated coupling of the pump light and the signal light through the first double-clad fiber 1111 and the second double-clad fiber 1112.

[0023] The flat end of the roof prism 12 is coated with a film that is highly reflective to the pump light and a film that increases the transmittance of the signal light. The angle a of the roof end of the roof prism 12 has a specific angle of 3.7°. The signal light filter film 13 is coated with a narrow-band filter film, so that the signal light passes through and the fluorescence is reflected outside the signal light path. The signal light filter film 13 is tilted at an angle greater than 0 degrees. The right-angle surface of the right-angle prism 14 is coated with a film that is highly reflective to the signal light, which is used to reflect the signal light.

[0024] The remaining pump light in the second-stage double-clad active fiber of the optical amplifier is input from the cladding of the first double-clad optical fiber 1111 and transmitted to the lens 113, collimated by the lens 113 and transmitted to the roof prism 12, reflected back to the lens 113 by the plane end of the roof prism 12, coupled to the cladding of the second double-clad optical fiber 1112 by the lens 113 and transmitted, and then incident on the first-stage double-clad active fiber of the optical amplifier.

[0025] The signal light and fluorescence amplified in the core of the first-stage double-clad active optical fiber of the optical amplifier are input from the core of the second double-clad optical fiber 1112 and transmitted to the lens 113, and are collimated by the lens 113 and transmitted to the roof prism 12. After passing through its flat end, the light is corrected when passing through an oblique angle surface of the roof prism, and the light with an angle of 0 degree is incident on the signal light filter diaphragm 13, and most of the fluorescence is reflected out of the light path by the signal light filter diaphragm 13 while the signal light is transmitted. After the signal light is reflected by the right-angle prism 14, the fluorescence is filtered out by the signal light filter diaphragm 13 again, and then incident from another oblique angle surface of the roof prism 12. After the transmission angle is corrected by the roof prism 12, it is coupled to the core of the first double-clad optical fiber 1111 by the lens 113, and finally enters the core of the second-stage double-clad active optical fiber of the optical amplifier for further amplification. Example

[0026] like Figure 4 As shown, the difference between the second embodiment of the present invention and the first embodiment is that the second embodiment uses another roof prism 14 and a reflector 15 to replace the right-angle prism 14 in the first embodiment, and the rest is the same as the first embodiment, which will not be repeated here.

[0027] The above describes the specific implementation of the present invention, but those skilled in the art should understand that this is only an example. Those skilled in the art can make various changes or modifications to this implementation without departing from the principle and essence of the present invention, but these changes and modifications are all within the scope of protection of the present invention.

Claims

1. An integrated device for suppressing spontaneous fluorescence in an optical fiber amplification system, characterized in that: It includes a dual optical fiber collimator, a roof prism, a signal light filter film and a right-angle prism which are arranged in sequence; The dual-fiber collimator is composed of a dual-fiber head, a lens and a glass sleeve. The dual-fiber head includes a first double-clad optical fiber, a second double-clad optical fiber and a capillary. The cladding of the first double-clad optical fiber is used to transmit pump light, and the core is used to transmit signal light; the cladding of the second double-clad optical fiber is used to transmit pump light, and the core is used to transmit signal light; the lens is used for collimating and coupling the pump light and the signal light through the first double-clad optical fiber and the second double-clad optical fiber, and the glass sleeve is used to fix the dual-fiber head and the lens; The flat end of the roof prism is coated with a film that is highly reflective of pump light and a film that increases transmittance of signal light, and is used to reflect the pump light collimated and output by the first double-clad optical fiber and the lens back to the lens and couple it to the cladding of the second double-clad optical fiber, and to couple the signal light output by the second double-clad optical fiber core and the lens to the signal light filter film and the right-angle prism group, and couple the signal light reflected by the right-angle prism to the core of the first double-clad optical fiber; The signal light filter film is coated with a narrow-band filter film, so that the signal light passes through and the fluorescence is reflected outside the signal light path; The right-angle surface of the right-angle prism is coated with a high-reflection film for signal light, which is used to reflect the signal light.

2. The integrated device for suppressing spontaneous fluorescence in an optical fiber amplification system according to claim 1, characterized in that: The angle a of the roof end of the roof prism is 3.7 degrees.

3. The integrated device for suppressing spontaneous fluorescence in an optical fiber amplification system according to claim 1, characterized in that: The signal light filter membrane is tilted at an angle greater than 0 degrees.

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