CN216670325U - Novel narrow-band light tunable optical filter - Google Patents

Abstract

The utility model discloses a novel narrow-band light tunable optical filter, which relates to the technical field of optical communication and comprises an incident optical fiber and an emergent optical fiber, wherein lenses are arranged on the right sides of the incident optical fiber and the emergent optical fiber, a first grating is arranged on one side, away from the incident optical fiber and the emergent optical fiber, of the lens, the first grating is arranged in an inclined mode, a second grating is arranged on the lower side of the first grating, 1/4 wave plates are arranged on the lower side of the second grating, and a reflecting rotating mirror is arranged on the left side of 1/4 wave plates; through setting up first piece of grating and second piece of grating to the quantity that sets up first piece of grating and second piece of grating is a plurality of, and the quantity that sets up the reflection rotating mirror simultaneously is a plurality of, reaches the dispersion resolution ratio that improves the filter product through adjusting quantity, compares and changes the grating constant and improve dispersion resolution ratio in traditional technique, and the implementation effect of this scheme can not receive the restriction.

Description

Novel narrow-band light tunable optical filter

Technical Field

The utility model relates to the technical field of optical communication, in particular to a novel narrow-band light adjustable optical filter.

Background

Tunable Optical Filters (TOF) are optical devices used for wavelength selection, which can select a desired wavelength from a plurality of different incident wavelengths, while the remaining wavelengths of light are not output and the wavelength of the output optical signal can be adjusted as desired.

The function of the tunable optical filter is to selectively output a wavelength (frequency) selective optical device of a specific wavelength from input optical signals having different frequencies.

The adjustable Optical filter can be applied to multiple aspects such as a reconfigurable Optical path up-down multiplexer/demultiplexer (ROADM), an Optical cross connect (OXC) system and a sensing network in a DWDM system, can also be applied to the current 'intelligent' network, such as an Optical Channel Monitor (OCM) module and an Optical Power Monitor (OPM) module, and can also be used as a broadband filter for reducing noise in the system.

The adjustable optical filter mainly comprises an F-P cavity filter, a Mach-Zehnder filter, an electro-optical filter, a grating type filter, an optical fiber Bragg grating filter and the like. At present, most optical filters are filters based on MEMS technology platforms, and the filters realize wavelength adjustability in an operating waveband based on MEMS angle adjustability.

The grating type adjustable filter is characterized in that incident light waves are subjected to light splitting processing by using a grating element in a light path, so that light with different wavelengths is emitted at different angles after passing through a grating, and the MEMS rotating mirror deflects at different angles by adjusting the voltage of the MEMS rotating mirror, so that the output light wavelength is adjustable. In such an optical path, the main contribution to the dispersion function is the grating. The denser the number of grating lines, the stronger the dispersive power, and the narrower the bandwidth of the corresponding optical filter.

From the grating equation nd (sin θ in + sin θ m) ═ m λ, we know that: when the wavelength, the ambient refractive index, and the grating diffraction order are fixed, the grating constant d cannot be any value. Since the incident angle thetain and the diffraction angle thetam can only be acute angles, considering the mechanical arrangement of each optical component and the size miniaturization requirement of products, the incident angle thetain and the diffraction angle thetam are generally required to be between 15 and 75 degrees. Thus, the grating constant can only be within a certain range. Therefore, it is limited to improve the dispersion resolution of the product by changing the grating constant.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects in the prior art, the utility model aims to provide a novel narrow-band light adjustable optical filter which has the characteristic of increasing the number of gratings to improve the dispersion resolution of a filter product.

In order to achieve the purpose, the utility model provides the following technical scheme:

the utility model provides a novel narrow band light tunable optical filter, includes incident optic fibre and emergent optic fibre, its characterized in that, the right side of incident optic fibre and emergent optic fibre is provided with lens, and one side that incident optic fibre and emergent optic fibre were kept away from to lens is provided with first piece of grating, and first piece of grating sets up for the slope, and the downside of first piece of grating is provided with second piece of grating, and the downside of second piece of grating is provided with 1/4 wave plates, and the left side of 1/4 wave plates is provided with the reflection rotating mirror.

Furthermore, the number of the first piece of grating and the second piece of grating is a plurality, and the number limit has no upper limit, the number of the reflecting rotating mirrors is a plurality, the reflecting rotating mirrors can be the combination of MEMS reflecting rotating mirrors and common reflecting mirrors, and the reflecting rotating mirrors can be distributed at different positions.

By adopting the technical scheme, the number of the reflecting rotating mirrors is set to be a plurality of reflecting rotating mirrors, and in order to fold a light path, the reflecting rotating mirrors can be better packaged, namely the reflecting rotating mirrors can be a combination of an MEMS reflecting rotating mirror and a common reflecting mirror, namely 1 MEMS reflecting rotating mirror and a plurality of common reflecting mirrors, or a plurality of MEMS reflecting rotating mirrors and a common reflecting mirror, and also can be a plurality of MEMS reflecting rotating mirrors and a plurality of common reflecting mirrors.

Further, the 1/4 wave plate is placed between the MEMS mirror and the second grating.

By adopting the technical scheme, the 1/4 wave plate is arranged between the MEMS reflecting mirror and the second grating, and the PDL of the product is mainly reduced.

In conclusion, the utility model has the following beneficial effects:

in this scheme, through setting up first piece grating and second piece grating to the quantity that sets up first piece grating and second piece grating is a plurality of, and the quantity that sets up the reflection simultaneously changes the mirror is a plurality of, reaches the dispersion resolution ratio that improves the filter product through adjusting quantity, compares and changes the grating constant and improve dispersion resolution ratio in traditional technique, and the implementation effect of this scheme can not receive the restriction.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

In the figure: 1. an incident optical fiber; 2. an outgoing optical fiber; 3. a lens; 4. a first grating; 5. a second piece of grating; 6. 1/4 a wave plate; 7. a reflecting rotating mirror.

Detailed Description

Referring to fig. 1, the present invention provides a technical solution: the utility model provides a novel narrow band light tunable optical filter, includes incident optical fiber 1 and emergent optical fiber 2, the right side of incident optical fiber 1 and emergent optical fiber 2 is provided with lens 3, and one side that incident optical fiber 1 and emergent optical fiber 2 were kept away from to lens 3 is provided with first piece grating 4, and first piece grating 4 sets up for the slope, and the downside of first piece grating 4 is provided with second piece grating 5, and the downside of second piece grating 5 is provided with 1/4 wave plate 6, and the left side of 1/4 wave plate 6 is provided with reflection rotating mirror 7.

The number of the first grating 4 and the second grating 5 is several, and the number limit has no upper limit, the number of the reflection rotating mirror 7 is several, the reflection rotating mirror 7 can be a combination of an MEMS reflection rotating mirror and a common reflection mirror, several reflection rotating mirrors 7 can be distributed at different positions, 1/4 wave plate 6 is placed between the MEMS reflection rotating mirror and the second grating 5, PDL of the product is reduced by setting 1/4 wave plate 6, PDL of the product is mainly caused by a dispersion element grating, after 1/4 wave plate 6, the phase has 1/2 pi change, after the reflection mirror, the phase has pi change, 1/4 wave plate 6 and the reflection mirror are combined, the embodiment in the grating is that the light in the TE mode in the grating before passing 1/4 wave plate 6 and the reflection mirror, and after passing 1/4 wave plate 6 and the reflection mirror, the light becomes the TM mode, whereas light that was in the TM mode in the grating before passing through 1/4 wave plate 6 and mirror will become in the TE mode after passing through 1/4 wave plate 6 and mirror.

The working principle is as follows: incident light enters a light path through an incident optical fiber 1, is changed into collimated light after passing through a lens 3, is diffracted after passing through a first grating 4 and a second grating 5, light with different wavelengths can be separated by a certain angle, finally reaches a reflecting rotating mirror 7 through an 1/4 wave plate 6, returns in a light original path after being reflected by a reflecting mirror, is output from an emergent optical fiber 2, the voltage of an MEMS reflecting rotating mirror in the light path is changed, and light with different wavelengths is output from the emergent optical fiber 2, so that the purpose of adjustable filtering is realized.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims (6)

1. The utility model provides a novel narrow band light tunable optical filter, includes incident optical fiber (1) and emergent optical fiber (2), a serial communication port, the right side of incident optical fiber (1) and emergent optical fiber (2) is provided with lens (3), one side that incident optical fiber (1) and emergent optical fiber (2) were kept away from in lens (3) is provided with first piece grating (4), first piece grating (4) set up for the slope, the downside of first piece grating (4) is provided with second piece grating (5), the downside of second piece grating (5) is provided with 1/4 wave plate (6), the left side of 1/4 wave plate (6) is provided with reflection rotating mirror (7).

2. A novel narrow-band light tunable optical filter according to claim 1, wherein the number of the first sheet of grating (4) and the second sheet of grating (5) is several, and there is no upper limit to the number.

3. A novel narrow-band light tunable optical filter according to claim 1, characterized in that the number of the reflecting rotating mirror (7) is several.

4. A novel narrow-band optical tunable optical filter according to claim 3, characterized in that the reflective turning mirror (7) is a combination of MEMS reflective turning mirror and ordinary mirror.

5. A novel narrow-band light tunable optical filter according to claim 4, characterized in that several said reflecting mirrors (7) can be distributed at different positions.

6. A novel narrow-band light tunable optical filter according to claim 1, wherein said 1/4 wave plate (6) is placed between the MEMS mirror and the second grating (5).

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