CN217561774U - Miniature free space multichannel closes ripples subassembly - Google Patents

Abstract

The utility model provides a miniature free space multichannel composite wave component, which comprises a substrate, wherein the substrate is divided into a first area and a second area, the first area and the second area are in mirror symmetry, one surface of the substrate of the first area is provided with an optical filter in parallel, the other surface of the substrate of the first area is provided with a high reflection film and a light outlet, and the light outlet is internally plated with an anti-reflection film; the filter, the high-reflection film and the anti-reflection film on the glass substrate of the second area are in mirror symmetry with the first area; the rear side of the substrate is also provided with a PBS prism, one side surface of the PBS prism is provided with two prism light inlets, and the two prism light inlets are respectively corresponding to the polarization components; the other side of the PBS prism is provided with a prism light outlet. Compared with the prior art, the multi-channel wave-combining component is divided into two mirror-symmetrical parts so as to reduce the reflection times on the surface of a light beam WDM film and reduce the loss; the light beam combination waves respectively output by the first area and the second area are realized by transmitting P polarized light and reflecting S polarized light through the PBS prism, are irrelevant to the wavelength, and avoid the problem of the existing combination waves.

Description

Miniature free space multichannel closes ripples subassembly

Technical Field

The utility model relates to an optical fiber communication field, especially a miniature free space multichannel closes ripples subassembly.

Background

As shown in fig. 1, which is a first prior art solution, an eight-channel Arrayed Waveguide Grating AWG (Arrayed Waveguide Grating) is provided, and each channel beam is input into the AWG chip from each channel Waveguide and is input into the Arrayed Waveguide at different positions through a Free propagation region FPR (Free propagation region) at the input end. The phase difference generated by different optical path lengths of the channel light beams to the waveguides of the arrayed waveguide is compensated by the arrayed waveguides with different lengths, and the channel light beams are focused into the output waveguide in the output end FPR. The difference caused by different wavelengths of the light beams in the eight channels is compensated by entering the input end FPR from different positions, so that the light beams of all the channels can be focused into the output waveguide by the same array. However, since the refractive index of the AWG chip itself and the length of the waveguide vary with temperature, and the heat distribution of each part of the AWG chip is not uniform, the central wavelength of each channel and the position of the coherence enhancement at the output FPR vary greatly with temperature, affecting the optical performance. Based on the temperature sensitive characteristic of the AWG, a corresponding temperature control component needs to be additionally added or a component which performs self-compensation within a certain temperature range is added in the AWG, so that the AWG can stably work within the required working temperature range; which would increase the overall space size and assembly cost.

As shown in fig. 2, in a second prior art, a TFF (Thin Film filter) eight-channel wave combining component connected by a dual-fiber collimator is disclosed, where the first and second wave combining components are both a four-channel wave combining component that is pasted on a bottom plate, one side of the first and second wave combining components is pasted with a Thin Film band-pass filter 1, and one side of the first and second wave combining components is plated with an AR Film 2 and an HR Film 3. Light beams with different wavelengths of four channels in the first wave combining component and the second wave combining component are input from one side of the filter, and are output from the position of the glass substrate coated with the AR film after being reflected by one side of the glass substrate coated with the HR film and the band-pass filter. And the light beams output by the second wave combining component enter the double-fiber collimator through the filter plate and are coupled into the output optical fiber. The light output by the first wave-combining component is input into the single-fiber collimator and output from the double-fiber collimator through the optical fiber, and is reflected by the filter plate on the bottom plate of the second wave-combining component in front of the collimator, enters the double-fiber collimator again and is coupled into the output optical fiber.

As shown in fig. 3, which is a third prior art scheme, a TFF eight-channel wave-combining component connected by Z-Block, two glass substrates, one side of which is pasted with a thin-film band-pass filter 1, and the other side of which is plated with an HR film 3 and an AR film 2, are abutted against each other, and are pasted on a bottom plate in a mirror symmetry manner by taking the abutted surfaces as symmetry surfaces; light beams with different wavelengths of four channels in the first glass substrate and the second glass substrate are input from one side of the filter, and are output from the position of the glass substrate coated with the AR film after being reflected by one surface of the glass substrate coated with the HR film and the surface adhered with the band-pass filter; the light beam output by the first glass substrate enters the third glass substrate through the AR sheet, the AR film and the HR film are plated on one side of the third glass substrate, the AR sheet, the HR sheet and the thin film filter are attached to the other side of the third glass substrate, and the light beam is reflected for four times by the HR film, the HR sheet and the thin film filter and is output from the AR film. The light beam output by the second glass substrate enters the thin film filter, enters the third glass substrate, is output from the AR film on the other side and is superposed with the light beam output by the first glass substrate; the output beam of the third glass substrate is reflected to the position of required output by the 45-degree glass block coated with the AR film.

Aiming at the second technical scheme and the third technical scheme, the thin film filter used by the TFF type wavelength division multiplexing component has a common problem, and one surface of the thin film filter plated with the WDM film is not plane. Because the WDM film has certain stress, one surface of the film plated with the WDM film is drawn into a convex spherical surface with certain curvature, the divergence angle and the diameter of the light beam are enlarged after the collimated light beam is reflected by the WDM film of the convex spherical surface, after the light beam is diverged to a certain degree and exceeds the effective clear aperture of the component, only the part of the light beam in the effective clear aperture can be normally output, the diameter and the divergence angle of the cut light beam are larger, and the coupling efficiency is reduced. Therefore, a wavelength division multiplexing module of TFF type needs to avoid the light beam from being reflected multiple times by the convex WDM film. Referring to fig. 2 and 3, in order to avoid the light beam from being reflected and dispersed by the WDM film for many times, the prior art schemes two and three choose to split the 8-channel wave-combining component into two pieces of 4-channel wave-combining components. In the second prior art, the front 4 channels of input light in the first glass substrate are reflected for multiple times to form a beam, and the beam is output from the AR film, coupled into the single-fiber collimator, and transmitted to the double-fiber collimator at the other end through the optical fiber. After being emitted from the dual-fiber collimator, the light is reflected back to the dual-fiber collimator by the film filter in front and is coupled into the output optical fiber. The rear 4 channels of input light in the second glass substrate are reflected to form a beam and output from the AR film, and the output light transmits through the thin film filter in front and is coupled into the output optical fiber of the double-fiber collimator. In the third prior art, in the first and second glass substrates, the front and rear 4-channel input lights are respectively combined into a beam of light after being reflected for multiple times and then output from the AR areas of the two glass substrates. The output light of the first glass substrate enters the third glass substrate from the AR film and exits from the AR film area under the reflection of the HR film, the HR sheet and the filter. The output light of the second glass substrate enters the third glass substrate from the filter and exits from the AR film area. In summary, in both the second and third prior art solutions, when the output light of the two 4-channel wave-combining assemblies is combined into one beam, a thin film filter is used to reflect the front four-channel light beams and transmit the rear four-channel light beams. The wavelength band capable of low-loss long-distance transmission in the existing optical fiber is limited, and in order to improve the information transmission efficiency, the existing optical communication can reduce the channel interval as much as possible within the limited wavelength range and increase the channel bandwidth. Therefore, in the second and third prior art solutions, the smaller the channel interval between the two channels with the closest central wavelengths between the front 4-channel input light and the rear 4-channel input light, the larger the bandwidth, and the more difficult the filter connected to the first and second 4-channel wave-combining components is to be manufactured. For example, when eight central wavelengths commonly used for transmitting existing LAN WDM, such as 1309.14nm, 1304.58nm, 1300.05nm, 1295.56nm, 1286.66nm, 1282.26nm, 1277.89nm, and 1273.54nm, if the channel bandwidth is 2.1nm, the width of the Deadband (transition region) between the transmission band and the reflection band of the filter is only 6.8nm, which is difficult to implement.

SUMMERY OF THE UTILITY MODEL

To the above problem, the present invention provides a free space type, wavelength division channel number arbitrary, temperature sensitivity low, output beam diameter small, high isolation multi-channel wave-combining component.

The utility model adopts the technical proposal that:

a micro free space multi-channel wave-combining component is characterized by comprising a substrate, wherein the substrate is divided into a first area and a second area, the first area and the second area are in mirror symmetry, one surface of the substrate in the first area is provided with at least two optical filters which are used for allowing light with specific wavelengths to pass through in a side-by-side mode, the other surface of the substrate in the first area is provided with a high-reflection film which is used for reflecting the light which does not pass through the optical filters and reflects back and a light outlet which is used for emitting light beams, and the light outlet is plated with an anti-reflection film; the filter, the high-reflection film and the anti-reflection film on the glass substrate of the second area are in mirror symmetry with the first area; the rear side of the substrate is also provided with a PBS prism used for combining the light beams from the first area light outlet and the second area light outlet, one side surface of the PBS prism is provided with two prism light inlets, and the two prism light inlets are respectively and correspondingly provided with a polarization component used for adjusting the polarization state of the light beams from the first area light outlet and the second area light outlet and isolating the reversely transmitted light beams; and the other side surface of the PBS prism is provided with a prism light outlet for the combined wave emergence of the light beams entering from the light inlets of the two prisms.

Preferably, the polarization component comprises a half-wave plate and a polarization isolator, the half-wave plate is attached to the light inlet of the prism, the light path of the light inlet of the polarization isolator is overlapped with the light path of the light outlet on the corresponding substrate, and the light beam emitted from the first area is adjusted into S light entering the PBS prism through the polarization isolator and the half-wave plate and is reflected by the PBS surface in the PBS prism; the light beam emitted from the second area is adjusted into P light entering the PBS prism through the polarization isolator and the half-wave plate, and the P light is transmitted by the PBS surface in the PBS prism.

Preferably, the polarization component comprises polarization isolators, a light inlet light path of each polarization isolator is overlapped with a light outlet light path on the corresponding substrate, an included angle between polarization directions of light beams incident into the first area and the second area is 90 degrees, and an angle formed by the polarization directions of the two light beams and the bottom surface of the substrate is 45 degrees; when a light beam passes through the two polarization-related isolators, the polarization direction of the light beam is clockwise rotated by 45 degrees by the Faraday rotation plate in the middle of the isolators, the emergent light beam of the first glass substrate is rotated into S light, the emergent light beam of the second glass substrate is rotated into P light, and the PBS prism can directly realize wave combination.

Preferably, the glass substrate, the PBS prism and the polarization component are arranged on the bottom plate.

Preferably, the glass substrate can be formed by cutting one glass panel or splicing two parallelogram glass panels.

More preferably, the angle of the parallelogram glass panel is arbitrary and is limited by the range of incidence angles allowed by the normal operation of the filter.

Preferably, the number of the optical filters is N,4 ≦ N ≦ 8.

Preferably, the light with the specific wavelength is linearly polarized light, and the polarization direction can be set according to requirements.

Compared with the prior art, the beneficial effects of the utility model reside in that: the utility model provides a micro free space multi-channel wave-combining component, which is divided into two mirror-symmetrical parts to reduce the reflection times of light beams on a WDM film surface with a certain curvature radius and reduce the loss; meanwhile, the light beam combination waves respectively output by the first area and the second area are realized by transmitting P polarized light and reflecting S polarized light through the PBS prism related to polarization, are irrelevant to wavelength, and the problems of small transition area and difficult film coating of a thin film filter used in the existing combination waves are solved.

Drawings

FIG. 1 is a schematic diagram of a first prior art solution;

FIG. 2 is a schematic diagram of a second prior art;

FIG. 3 is a schematic diagram of a third prior art solution;

fig. 4 is a schematic view of an embodiment of a micro free-space multi-channel wave-combining assembly according to the present invention;

fig. 5 is a schematic diagram of the polarization direction of input light of a first embodiment of a micro free-space multi-channel wave-combining component according to the present invention;

fig. 6 is a schematic view of an embodiment of a micro free-space multi-channel wave-combining assembly according to the present invention.

Detailed Description

The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 4 to fig. 6 illustrate a preferred embodiment of a micro free-space multi-channel wave-combining assembly according to the present invention. As shown in fig. 4 to 6, the micro free-space multi-channel wave-combining component includes a substrate 10, the substrate is divided into a first region 11 and a second region 12, the first region 11 and the second region 12 are mirror-symmetric, one surface of the substrate in the first region is attached with at least two filters 111 for allowing light with specific wavelength to pass through, the other surface of the substrate in the first region is provided with a high-reflection film 112 for reflecting light that does not pass through the filters and a light outlet for emitting light beams, and the light outlet is plated with an anti-reflection film 113; the filter 121, the high-reflection film 122 and the anti-reflection film 123 on the second area substrate are in mirror symmetry with the first area; the rear side of the base plate is also provided with a PBS prism 20 used for combining the wave of the light beams coming out from the first area light outlet and the second area light outlet, one side surface of the PBS prism is provided with two prism light inlets, and the two prism light inlets are respectively corresponding to a polarization component 30 used for adjusting the polarization state of the light beams coming out from the first area light outlet and the second area light outlet and isolating the reversely transmitted light beams; the other side of the PBS prism is provided with a prism light outlet for the combined wave emergence of the light beams entering from the light inlets of the two prisms, the light beams enter from the channel filters on the substrates of the two regions, the polarization directions of the channel light beams on the substrate of the same region are the same, the light of the previous channel in each region is overlapped with the light path of the incident light beam of the next channel after being reflected by the WDM film on the high-reflection film 112 and the filter film of the next channel in sequence, the light beams are combined into the same light beam, finally pass through the anti-reflection film 113 in the light outlet on the substrate of the region and enter the polarization component 30, the light beam emerging from the first region is adjusted into the S light entering the PBS prism and is reflected by the PBS film surface in the PBS prism; the light beam emitted from the second area is adjusted into P light entering the PBS prism and is transmitted by the PBS surface in the PBS prism; the two beams of light are overlapped in the PBS prism after being totally reflected by the PBS film surface, and the combined wave is formed into a beam of light which is output from the light outlet of the prism.

It is noted that the light with the specific wavelength is linearly polarized light, and the polarization direction can be set according to requirements.

As shown in fig. 4, the polarization component 30 includes polarization isolators 31, and the light path of the light inlet of each polarization isolator 31 overlaps the light path of the light outlet on the corresponding substrate; when the included angle between the polarization directions of the light beams incident to the first region and the second region is 90 degrees, the included angle between the polarization directions of the two light beams and the bottom surface of the substrate is 45 degrees, as shown in fig. 5; when a light beam passes through the two polarization-related isolators, the polarization direction of the light beam is clockwise rotated by 45 degrees by the Faraday rotation sheet in the middle of the isolators, an emergent light beam on the first area substrate is rotated into S light, an emergent light beam on the second area substrate is rotated into P light, the two light beams are overlapped in a PBS prism through the light path after being totally reflected by the PBS surface, and the two light beams are combined into one light beam which is output from the light outlet of the prism.

As shown in fig. 6, the polarization component includes a half-wave plate 32 and a polarization isolator 31, the half-wave plate 32 is attached to the light entrance of the prism, the light path of the light entrance of the polarization isolator 31 is overlapped with the light path of the light exit on the corresponding substrate, the light beam emitted from the first area passes through the corresponding polarization isolator 31 and the half-wave plate 32, is adjusted to be S light entering the PBS prism, and is reflected by the PBS film surface in the PBS prism; the light beams emitted from the second area pass through the corresponding polarization isolator 31 and the half-wave plate 32, are adjusted into P light entering the PBS prism, and are transmitted by the PBS surface in the PBS prism, two light beams are overlapped in the PBS prism after being totally reflected by the PBS surface, and the light beams are combined into one light beam and output from the light outlet of the prism. The light beams with different input polarization directions correspond to the half-wave plates with different optical axis directions.

The polarization isolator utilizes the basic principle of Malus law and Faraday magneto-optical effect of polarized light, and the free space isolator has the basic structure comprising one magnetic ring, one Faraday rotator and two polarizing plates, the Faraday rotator is located between the two polarizing plates, and the optical axes of the two polarizing plates form an included angle of 45 degrees; linearly polarized light which is incident in the positive direction is transmitted smoothly by rotating the Faraday rotation plate anticlockwise by 45 degrees to the transmission axis direction of the second polarization plate along the transmission axis direction of the first polarization plate; the polarization direction of linearly polarized light which is incident in the reverse direction is along the transmission axis direction of the second polaroid, and the linearly polarized light is rotated by 45 degrees anticlockwise through the Faraday rotation plate to be vertical to the transmission axis direction of the first polaroid, and is isolated without transmission light.

The glass substrate 10, the PBS prism 20, and the polarizing component 30 are disposed on the base plate 40.

The substrate 10 may be cut from a single glass panel or may be formed by splicing two parallelogram-shaped glass panels 101. The angle of the parallelogram glass panel is random and is limited by the range of incidence angles allowed by the normal work of the filter.

It should be noted that, in the multi-channel wave-combining component, the number of channels is arbitrary, and the increase or decrease of the number of channels only needs to lengthen or shorten the length of the substrate and add or subtract the filters of the corresponding channels. Considering that the cumulative loss of TFF (Thin Film Filter) is not large when the number of channels is small (less than 4), the loss of the prior art structure is enough to satisfy various requirements, and when the number of channels is large (more than 8), the cost of AWG (Arrayed Waveguide Grating) is not related to the number of channels, so the cost of AWG is dominant when the loss and other parameters satisfy the requirements. Therefore, in general, the multiplexing component is more preferable when the number of channels is between 4 and 8. Therefore, the number of the optical filters is preferably N,4 ≦ N ≦ 8.

To sum up, the technical scheme of the utility model can be fully effectual the above-mentioned utility model purpose of realization, just the utility model discloses a structure and functional principle all obtain abundant verification in the embodiment, can reach anticipated efficiency and purpose, do not deviating from the utility model discloses a under the prerequisite of principle and essence, can make multiple change or modification to the embodiment of utility model. Therefore, the present invention includes all the alternative contents within the scope mentioned in the claims, and all the equivalent changes made within the claims of the present invention belong to the claims of the present application.

Claims (8)

1. A micro free space multi-channel wave-combining component is characterized by comprising a substrate, wherein the substrate is divided into a first area and a second area, the first area and the second area are in mirror symmetry, one surface of the substrate in the first area is provided with at least two optical filters which are used for allowing light with specific wavelengths to pass through in a side-by-side mode, the other surface of the substrate in the first area is provided with a high-reflection film which is used for reflecting the light which does not pass through the optical filters and reflects back and a light outlet which is used for emitting light beams, and the light outlet is plated with an anti-reflection film; the filter, the high-reflection film and the anti-reflection film on the glass substrate of the second area are in mirror symmetry with the first area; the rear side of the substrate is also provided with a PBS prism used for combining the light beams from the first area light outlet and the second area light outlet, one side surface of the PBS prism is provided with two prism light inlets, and the two prism light inlets are respectively and correspondingly provided with a polarization component used for adjusting the polarization state of the light beams from the first area light outlet and the second area light outlet and isolating the reversely transmitted light beams; the other side surface of the PBS prism is provided with a prism light outlet for the combined wave emergence of the light beams entering from the light inlets of the two prisms.

2. The miniature free-space multichannel multiplexing assembly of claim 1, wherein: the polarization component comprises a half-wave plate and a polarization isolator, the half-wave plate is attached to a light inlet of the prism, a light inlet light path of the polarization isolator is overlapped with a light outlet light path on the corresponding substrate, and a light beam emitted from the first area is adjusted into S light entering the PBS prism through the polarization isolator and the half-wave plate and is reflected by a PBS film surface in the PBS prism; the light beam emitted from the second area is adjusted into P light entering the PBS prism through the polarization isolator and the half-wave plate, and the P light is transmitted by the PBS surface in the PBS prism.

3. The miniature free-space multichannel multiplexing assembly of claim 1, wherein: the polarization component comprises polarization isolators, a light inlet light path of each polarization isolator is overlapped with a light outlet light path on the corresponding substrate, an included angle between polarization directions of light beams incident into the first area and the second area is 90 degrees, and an angle formed by the polarization directions of the two light beams and the bottom surface of the substrate is 45 degrees; when a light beam passes through the two polarization-related isolators, the polarization direction of the light beam is clockwise rotated by 45 degrees by the Faraday rotation plate in the middle of the isolators, the emergent light beam of the first glass substrate is rotated into S light, the emergent light beam of the second glass substrate is rotated into P light, and the PBS prism can directly realize wave combination.

4. The miniature free-space multichannel multiplexing assembly of any one of claims 2 or 3, wherein: the glass substrate, the PBS prism and the polarization component are all arranged on the bottom plate.

5. The miniature free-space multichannel multiplexing assembly of claim 1, wherein: the glass substrate can be formed by cutting one glass panel or splicing two parallelogram glass panels.

6. The miniature free-space multichannel multiplexing assembly of claim 5, wherein: the angle of the parallelogram glass panel is random and is limited by the range of incidence angles allowed by the normal work of the filter.

7. The miniature free-space multichannel multiplexing assembly of claim 1, wherein: the number of the optical filters is N, and N is more than or equal to 4 and less than or equal to 8.

8. The miniature free-space multichannel multiplexing assembly of claim 1, wherein: the light with the specific wavelength is linearly polarized light, and the polarization direction can be set according to requirements.

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