Integrated optical device based on surface natural reflection light splitting

Abstract

The utility model relates to an integrated optical device based on surface natural reflection light splitting. The integrated optical device comprises a single-fiber collimator, a beam splitter prism, a double-fiber collimator, an outer glass sleeve and a crystal support. The beam splitter prism is of an integrated structure formed by gluing a first prism and a second prism, the first prism and the second prism are made of different materials, the beam splitter prism divides a signal light beam input by an incident optical fiber into monitoring light and signal light in proportion, and the two divided light beams are emitted from the output end face of the beam splitter prism; and the optical fibers are coupled into the double-optical-fiber collimator. According to the utility model, light splitting is carried out by adopting natural reflection of a bonding interface of two light-transmitting materials of different materials, and a light splitting film does not need to be plated on the interface, so that the manufacturing difficulty is reduced, the process is simplified, and the cost is reduced; and the refractive index tolerance of the light-transmitting material can be controlled at a quite stable level, so that accurate small-proportion light splitting is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to laser radar technical field, concretely relates to an integrated optical device based on surface natural reflection light splitting. BACKGROUND

[0002] As one of the commonly used components in optical devices, the light splitting prism is an optical element capable of separating the energy of specific incident light, and therefore is widely used. Most of the current light splitting prism schemes are to split light by coating a light splitting film or using a polarization state separation method. For application scenarios with a small light splitting ratio (for example, a light splitting ratio of 1:999, i.e., a light splitting of 0.1%), the coating of the light splitting film is difficult, and the light splitting precision is not high. SUMMARY

[0003] The utility model aims at overcoming the prior art's insufficient, provide an integrated optical device based on surface natural reflection light splitting.

[0004] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0005] An integrated optical device based on surface natural reflection light splitting, characterized by comprising a single-fiber collimator, a light splitting prism, a double-fiber collimator, an outer glass sleeve, and a crystal support.

[0006] The single-fiber collimator, the light splitting prism, and the double-fiber collimator are sequentially connected to the shaft hole of the outer glass sleeve.

[0007] The single-fiber collimator includes a single-fiber head, a first lens, and a first glass sleeve, the first glass sleeve is used to fix the single-fiber head and the first lens, the single-fiber head includes a first capillary and an incident optical fiber, the incident optical fiber is a single-mode optical fiber and is used for signal light input; the double-fiber collimator includes a double-fiber head, a second lens, and a second glass sleeve, the second glass sleeve is used to fix the double-fiber head and the second lens, the double-fiber head includes a second capillary, an output optical fiber, and a monitoring optical fiber, the output optical fiber is a single-mode optical fiber and is used for outputting signal light, and the monitoring optical fiber is a multi-mode optical fiber and is used for outputting monitoring light.

[0008] The light splitting prism is an integral structure composed of a first prism and a second prism by gluing, the materials of the first prism and the second prism are different, the light splitting prism divides the signal light beam input by the incident optical fiber into monitoring light and signal light in proportion, the two divided light beams are emitted from the output end face of the light splitting prism and coupled into the double-fiber collimator.

[0009] Further, the light splitting prism is placed on the crystal support inside the outer glass sleeve.

[0010] Furthermore, the end faces of the incident optical fiber and the output optical fiber are respectively connected to End-cap or TEC optical fibers.

[0011] Furthermore, the first and second lenses are C-LENS or G-LENS, and both the light-transmitting surfaces of the first and second lenses are coated with an anti-reflective film.

[0012] Furthermore, the first prism is made of SILICA fused silica, and the second prism is made of H-BaK4 barium crown glass.

[0013] Furthermore, the first prism is made of SILICA fused silica, and the second prism is made of K9 crown glass.

[0014] This invention employs the above technical solution, using a single-fiber collimator, a first lens, a beam-splitting prism, a second lens, and a dual-fiber collimator in a paired combination to form a beam-splitting device with a compact structure. This invention utilizes the natural reflection from the interface of two light-transmitting materials of different materials for beam splitting, eliminating the need for a beam-splitting film on the interface, thus reducing manufacturing difficulty, simplifying the process, and lowering costs. Furthermore, the refractive index tolerance of the light-transmitting materials can be controlled at a fairly stable level, thereby ensuring precise small-ratio beam splitting. Attached Figure Description

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0016] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0017] Figure 2 This is a schematic diagram of the single-fiber collimator in an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of the structure of the dual-fiber collimator in an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of a beam splitter prism structure;

[0020] Figure 5 This diagram illustrates the refraction and reflection components of light rays incident on different media.

[0021] In the figure: 11-Single fiber collimator; 111-Single fiber head; 1111-Incident fiber; 1112-First capillary; 1113-End-cap; 112-First glass sleeve; 113-First lens; 12-Outer glass sleeve; 13-Crystal support; 14-Beam splitter prism; 141-First prism; 1411-Incident end face of the first prism; 14111-Antireflection coating; 14112-High reflectivity coating; 1412(1421)-Cemented surface of the first and second prisms; 1422-Outgoing end face of the second prism; 142-Second prism; 15-Dual fiber collimator; 151-Dual fiber head; 1511-Output fiber; 1512-Monitoring fiber; 1513-Second capillary; 1514-End-cap; 152-Second glass sleeve; 153-Second lens. Detailed Implementation

[0022] like Figures 1-5 As shown, this utility model discloses an integrated optical device based on surface natural reflection beam splitting, including an outer glass sleeve 12 and a crystal support 13. A single fiber collimator 11, a beam splitter prism 14, and a dual fiber collimator 15 are sequentially connected to the shaft hole of the outer glass sleeve 12. The crystal support 13 is placed inside the outer glass sleeve 12, and the beam splitter prism 14 is placed on the crystal support 13.

[0023] The single-fiber collimator 11 includes a single fiber head 111, a first glass sleeve 112, and a first lens 113. The first glass sleeve 112 is used to fix the single fiber head 111 and the first lens 113. The single fiber head 111 includes a first capillary 1112 and an incident fiber 1111. The incident fiber 1111 is a single-mode fiber and is used for signal light input.

[0024] The dual-fiber collimator 15 includes a dual-fiber head 151, a second glass sleeve 152, and a second lens 153. The second glass sleeve 152 is used to fix the dual-fiber head 151 and the second lens 153. The dual-fiber head 151 includes a second capillary tube 1513, an output fiber 1511, and a monitoring fiber 1512. The output fiber 1511 is a single-mode fiber used for signal light output; the monitoring fiber 1513 is a multimode fiber used for monitoring light output.

[0025] The beam splitter 14 is a single structure formed by bonding the first prism 141 and the second prism 142 together. The first prism 141 and the second prism 142 are made of different materials. The beam splitter 14 splits the signal beam input from the incident optical fiber into monitoring light and signal light in proportion. The two beams are emitted from the output end face of the beam splitter 14 and coupled into the dual fiber collimator 15.

[0026] In this embodiment, the wavelength of the light beam is 1550nm, and the beam splitting ratio can reach 1:999 after splitting. The light beam is emitted from the single fiber head 111, collimated by the first lens 113, and then split into beams by the beam splitter prism 14 according to the designed ratio. The beam is then focused by the second focusing lens 153 and enters the dual fiber heads 151.

[0027] In this embodiment, the incident fiber 1111 is a single-mode fiber, and the outgoing end face is coated with an anti-reflection film.

[0028] The first lens 113 and the second lens 153 are C-LENS, with an anti-reflective coating on their light-transmitting surfaces. They can also be G-LENS or other lenses that can collimate (focus) the outgoing beam.

[0029] The beam splitter 14 is composed of a first prism 141 and a second prism 142. The first prism 141 is made of SILICA fused silica, and the second prism 142 is made of H-BaK4 barium crown glass. At 1550 nm, the refractive index of SILICA fused silica is 1.444, and the refractive index of H-BaK4 barium crown glass is 1.5356.

[0030] The lower half of the incident end face 1411 of the first prism 141 is coated with an anti-reflection film 14111, and the upper half is coated with a high-reflection film 14112.

[0031] The signal light and the monitoring light are split at the cemented surfaces 1412 / 1421 of prisms 141 and 142. The signal light is transmitted through the second prism 142 and coupled into the single-mode fiber 1512 through the second lens 153. The monitoring light is reflected at the cemented surfaces 1412 / 1421, reflected by surface 14112, enters the second prism 142, and is coupled into the multimode fiber 1511 through the second lens 142.

[0032] according to Figure 5 The beam splitting ratio of a cemented lens can be calculated using Fresnel's law:

[0033]

[0034]

[0035] Where n1 is the refractive index of the first prism, n2 is the refractive index of the second prism, θ1 is the incident angle of the beam onto the cemented surface, and θ2 is the refraction angle. Rs: reflectivity of s-rays; Ts: transmittance of s-rays; Rp: reflectivity of p-rays; Tp: transmittance of p-rays. Rs + Ts = 1, Tp + Tp = 1. The overall reflectivity of the cemented surface can be obtained as: Rn = (Rs + Rp) / 2, the overall signal light transmittance of the cemented surface as Tn = (Ts + Tp) / 2, and the further beam splitting ratio as Tap = Rn / Tn.

[0036] In this embodiment, the angle between the incident surface 1411 and the bottom surface of the first prism 141 is 55°, the angle between the surface 1411 and the surface 1412 is 2.63°, and the angle between the exiting end surface 1412 and the exiting end surface 1422 of the second prism is 7.71°.

[0037] Based on the materials of the first prism 141 and the second prism 142, and the angles of the prisms, the theoretical spectral splitting ratio Tap in this embodiment is calculated to be 0.0962%, or 30.16 dB. According to the general tolerance of the material refractive index of ±0.0008, the spectral splitting ratio ranges from 0.0929% to 0.09953%, or 30.02 dB to 30.32 dB. The two prisms can also be made of a combination of other materials, such as the first prism 141 being made of fused silica and the second prism 142 being made of K9 crown glass. The refractive index can be allocated according to the required spectral splitting ratio using a formula.

[0038] The specific embodiments of this utility model have been described above. However, 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 embodiment without departing from the principle and essence of this utility model, but all such changes and modifications fall within the protection scope of this utility model.

Claims

1. An integrated optical device based on surface natural reflection spectroscopy, characterized by: Single fiber collimator, light splitting prism, double fiber collimator, outer glass sleeve and crystal support are included. The single fiber collimator, light splitting prism and double fiber collimator are sequentially connected on the shaft hole of the outer glass sleeve. The single fiber collimator includes a single fiber head, a first lens and a first glass sleeve for fixing the single fiber head and the first lens, the single fiber head includes a first capillary and an incident fiber, the incident fiber is a single mode fiber for signal light input. The double fiber collimator includes a double fiber head, a second lens and a second glass sleeve for fixing the double fiber head and the second lens, the double fiber head includes a second capillary, an output fiber and a monitoring fiber, the output fiber is a single mode fiber for outputting signal light, and the monitoring fiber is a multi-mode fiber for outputting monitoring light. The light splitting prism is an integrated structure formed by gluing a first prism and a second prism, the first prism and the second prism are made of different materials, the light splitting prism splits the signal light beam input by the incident fiber into monitoring light and signal light in proportion, the two split light beams are emitted from the output end face of the light splitting prism and coupled into the double fiber collimator.

2. The integrated optical device based on natural reflection of surface according to claim 1, characterized in that: The light splitting prism is placed on the crystal support inside the outer glass sleeve.

3. The integrated optical device based on natural reflection of surface according to claim 1, characterized in that: The fiber end faces of the incident fiber and the output fiber are respectively connected with End-cap or TEC fiber.

4. The integrated optical device based on natural reflection of surface according to claim 1, characterized in that: The first lens and the second lens are C-LENS or G-LENS, and the light passing faces of the first lens and the second lens are coated with anti-reflection film.

5. The integrated optical device based on natural reflection of surface according to claim 1, characterized in that: The material of the first prism is SILICA fused quartz, and the material of the second prism is H-BaK4 barium crown glass.

6. The integrated optical device based on natural reflection of surface according to claim 1, characterized in that: The material of the first prism is SILICA fused quartz, and the material of the second prism is K9 crown glass.

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