CN202956503U

CN202956503U - Variable optical attenuator with wavelength dependent loss compensation function

Info

Publication number: CN202956503U
Application number: CN 201220676540
Authority: CN
Inventors: 绪海波; 高红强; 郑建华; 李连城
Original assignee: O Net Communications Shenzhen Ltd
Current assignee: O Net Technologies Shenzhen Group Co Ltd
Priority date: 2012-12-07
Filing date: 2012-12-07
Publication date: 2013-05-29
Anticipated expiration: 2022-12-07

Abstract

The utility model provides a variable optical attenuator with a wavelength dependent loss (WDL) compensation function. The variable optical attenuator comprises an input optical fiber, a lens, a reflector and an output optical fiber. The lens is an oblique angle-free lens, and is used for calibrating beams from the input optical fiber, and focusing the beams to the output optical fiber. Light of a first wavelength component is incident into the oblique angle-free lens at a certain angle, and is chromatically dispersed in a direction opposite to directions of the optical fibers to compensate the chromatic dispersion of the optical fibers, so that attenuation WDL is reduced; an angle between the input optical fiber and the output optical fiber is enlarged, so that return loss reaches over 50dB; and the oblique angle-free lens is adopted for the optical attenuator, so that the angle between the input and output optical fibers is enlarged to fulfill the aim of improving the WDL and lower cost.

Description

A kind of optical attenuator regulated with wavelength dependent loss compensation

Technical field

The utility model relates to the optical communication device technical field, particularly a kind of optical attenuator regulated with wavelength dependent loss compensation.

Background technology

Can regulate optical attenuator (Variable Optical Attenuation, hereinafter to be referred as VOA) and have a wide range of applications in optical communication, it is mainly for lowering or the control light signal.The most basic characteristic of optical-fiber network is adjustable, the particularly application in optical communication along with DWDM transmission system and EDFA, must carry out flat gain or channel power equilibrium on a plurality of optical signal transmission passages, to carry out dynamically saturated control at the optical receiver end, in optical-fiber network, yet need other signal is controlled, these all make VOA become wherein indispensable Primary Component.In recent years, occurred that multiple manufacture can regulate the technology of optical attenuator, but comprised mechanical type VOA, magneto-optic VOA, liquid crystal VOA, MEMS (micro electro mechanical system) VOA, thermo-optical VOA and acousto-optic VOA etc.Adopt MEMS (micro electro mechanical system) (Micro-electromechanical System, hereinafter to be referred as MEMS) adjustable optical attenuator made, except the optical property that keeps traditional VOA technology, also have that attenuation range is large, driving voltage is low, volume is little, be easy to that hyperchannel is integrated, fast response time, cost performance advantages of higher.MEMS VOA has reflective (mirror) VOA and diffraction-type (shutter) VOA.

For reflective MEMS VOA, the Wavelength Dependent Loss (Wavelength Dependent Loss, hereinafter to be referred as WDL) caused due to fibre-optical dispersion is the difficult problem that prior art need to solve.Particularly, when the decay of light wave is larger, the WDL problem is even more important.U.S. Pat 20070031104 has disclosed in adjustable optical attenuator (VOA) system, by adopt insert dispersion wedge (Compensator) between catoptron and lens compensate Wavelength Dependent Loss (WDL), but this patent has increased a dispersion optical wedge element, increased manufacturing cost, and the having relatively high expectations of the technique for fixing that the precision of dispersed light wedge itself and dispersion wedge and bonding agent are binded.The angle of wedge glass that another U.S. Pat 20100003003 has disclosed by the subsides of the plane of incidence at lens (c-lens) pair high dispersion improves the WDL problem, but the angle of wedge glass cost of the high dispersion in this patent is higher, the improvement of the WDL of the incident light of differential declines value is had to certain limitation.

Summary of the invention

The utility model provides a kind of incident light to the differential declines value can improve the reflective MEMS VOA of its WDL simultaneously.

The utility model provides a kind of optical attenuator regulated with wavelength dependent loss compensation, comprise: input optical fibre, lens, catoptron and output optical fibre, wherein said input optical fibre, the light beam that comprises the first and second wavelength components for emission, with the second wave length component, compare, the first wavelength component has shorter wavelength; Described output optical fibre, for receiving described light beam; Described catoptron, for receiving the light beam from described lens, and arrive described output optical fibre by described light beam through described reflection from lens, and the position, different angle of described catoptron causes decay in various degree, and causes intrinsic WDL; It is characterized in that: described lens be set to have optical axis without the oblique angle lens, the light beam for calibration from described input optical fibre, and described light beam is focused on to described output optical fibre; Make its side-play amount to the first wavelength component be different from the side-play amount to the second wave length component, compensate at least in part intrinsic WDL.

Wherein, preferred version is: the pitch angle of the front end face of described input optical fibre is 12 degree.

Wherein, preferred version is: the pitch angle of the front end face of described output optical fibre is 12 degree.

The utility model has the advantage of: at first, because the lens of optical attenuator of the present utility model adopt without the oblique angle lens, produce the dispersion with the optical fiber opposite direction, realize the compensation to fibre-optical dispersion, thereby realize reducing respectively to decay WDL; Secondly, increase the angle of incident optical and outgoing optical fiber, make more than return loss reaches 50dB; Finally, because the cost without the oblique angle lens reduces greatly than the dispersion compensation wedge of prior art and the cost of high-dispersion glass, therefore reduced production cost, and adopted better without the technology stability of oblique angle lens in VOA.

The accompanying drawing explanation

Below in conjunction with drawings and Examples, light channel structure of the present utility model is further illustrated.

The schematic diagram that Fig. 1 is the optical attenuator regulated with wavelength dependent loss compensation of the present utility model.

Embodiment

Below in conjunction with accompanying drawing, to the utility model band, the optical attenuator regulated with wavelength dependent loss compensation is described further.

As shown in Figure 1, according to VOA of the present utility model, comprise: input optical fibre 13, the lens 11 with optical axis OA, tiltable catoptron 12, and with the output optical fibre 14 of fibre core 16 and coating 17.In the ideal case, input optical fibre 13 and output optical fibre 14 are placed in fact respectively from the place of optical axis OA same distance, and catoptron 12 can be placed with vertical with optical axis to provide close to best coupling like this.The light component (such as ruddiness, blue light etc.) that incident beam comprises various different wave lengths, for example the first wavelength component and second wave length component.With the second wave length component of incident beam, compare, the first wavelength component has shorter wavelength; For example the first wavelength component can be red light and the second wave length component is blue light.This incident beam penetrates from input optical fibre 13, by lens 11 calibrations directed, through lens 11, arrives tiltable catoptron 12.Catoptron 12 makes input beam change direction, through lens 11, arrives output optical fibre 14.Wherein, the position, different angle of catoptron 12 causes decay in various degree, and causes intrinsic WDL.

For WDL is compensated, according to the utility model, lens 11 adopt without the oblique angle lens, the input beam for calibration from described input optical fibre 13, and described input beam is focused on to described output optical fibre 14; Make its side-play amount to the first wavelength component be different from the side-play amount to the second wave length component, compensate at least in part intrinsic WDL.At input optical fibre 11 and output optical fibre 14 front end faces (pigtail), inclined angle alpha is set simultaneously, wherein inclined angle alpha is selected the suitable number of degrees according to the requirement of fibre-optical dispersion and WDL, its scope is that between 10 degree to 15 degree, wherein the inclined angle alpha of the VOA in the utility model is preferably 12 degree.Specifically, in Fig. 1, have the effect of converging directional light without oblique angle lens 11, it is incorporated into reflective surface 11a and exit surface 11b, and incidence surface 11a is plane, and exit surface 11b is convex surface.For example, with the light center point (ruddiness) of the first wavelength component, compare, the central point of second wave length component (for example blue light) is larger by side-play amount after the focusing without oblique angle lens 11, the fibre core 16 of more close output optical fibre 14.Therefore, the shorter light of wavelength has with the fibre core 16 overlapping number percent higher than prior art, and compares former situation, and the insertion loss IL caused due to wavelength is less, thereby contrary with the impact of intrinsic WDL, thereby compensated at least in part intrinsic WDL.

The advantage the utlity model has like this is: at first, because the lens of optical attenuator of the present utility model adopt without the oblique angle lens, produce the dispersion with the optical fiber opposite direction, realize the compensation to fibre-optical dispersion, thereby realize reducing respectively to decay WDL; Secondly, increase the angle of incident optical and outgoing optical fiber, make more than return loss reaches 50dB; Finally, because the cost without the oblique angle lens reduces greatly than the dispersion compensation wedge of prior art and the cost of high-dispersion glass, therefore reduced production cost, and adopted better without the technology stability of oblique angle lens in VOA.

As described above, be only the utility model most preferred embodiment, and not for limiting scope of the present utility model, all equivalences of doing according to the utility model claim change or modify, and are all the utility model and contain.

Claims

1. the optical attenuator regulated with wavelength dependent loss compensation, comprise: input optical fibre, lens, catoptron and output optical fibre, described input optical fibre, the light beam that comprises the first and second wavelength components for emission, with the second wave length component, compare, the first wavelength component has shorter wavelength; Described output optical fibre, for receiving described light beam; Described catoptron, for receiving the light beam from described lens, and arrive described output optical fibre by described light beam through described reflection from lens, and the position, different angle of described catoptron causes decay in various degree, and causes intrinsic Wavelength Dependent Loss; It is characterized in that: described lens be set to have optical axis without the oblique angle lens, the light beam for calibration from described input optical fibre, and described light beam is focused on to described output optical fibre; Make its side-play amount to the first wavelength component be different from the side-play amount to the second wave length component, compensate intrinsic Wavelength Dependent Loss.

2. a kind of optical attenuator regulated with wavelength dependent loss compensation according to claim 1, it is characterized in that: the front end face of described input optical fibre arranges a pitch angle.

3. a kind of optical attenuator regulated with wavelength dependent loss compensation according to claim 2, it is characterized in that: the pitch angle of the front end face of described input optical fibre is set between 10 degree to 15 degree.

4. a kind of optical attenuator regulated with wavelength dependent loss compensation according to claim 1, it is characterized in that: the front end face of described output optical fibre arranges a pitch angle.

5. a kind of optical attenuator regulated with wavelength dependent loss compensation according to claim 4, it is characterized in that: the pitch angle of the front end face of described output optical fibre is set between 10 degree to 15 degree.