CN1375947A

CN1375947A - Waveguide grating array wave splitting/composing device with channel monitoring function

Info

Publication number: CN1375947A
Application number: CN02111429A
Authority: CN
Inventors: 符建
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-04-17
Filing date: 2002-04-17
Publication date: 2002-10-23
Anticipated expiration: 2022-04-17
Also published as: CN1177420C

Abstract

This invention is to provide an array wave guide (AWD) grating wave division/wave synthetic device with the function of channel monitor to wavelength-division-multiplex (WDM) system to monitor the wavelength channel informatino which can merge tow A W G into one unit in the present WDM optical transmission system with wave division/wave synthetic and channel monitor which has the characteristics of dividing one-way multi-wavelength light signal into multi-way signals of different wavelengths and merging multi-way different wavelengths signals into one-way multi-wavelengths signals with a thickness-reduction area on the outer layer of the output wave guide mounted a coupling piece with light power detectors in a certain angle with the coupling piece in which each light power detector sensing area should be aligned with related outupt wave guide.

Description

The Waveguide grating array wave splitting/composing device that channel monitoring function is arranged

Technical field: the invention belongs to the multichannel communication technology, relates in a kind of wavelength division multiplexing (WDM) system the device that can wave splitting/composing can carry out performance monitoring again to each wavelength channel.

Background technology: in the division multiplex fibre-optic communication wave system, before wavelength channel is re-used or after the demultiplexing, usually need must be monitored in real time luminous power, Optical Signal To Noise Ratio and the wavelength of each channel, with guarantee light signal in wdm system reliably, transmission stably, this is most important in wdm system.About the channel monitoring device or the existing many prior aries of assembly of array waveguide grating, for example application number is 00100262.7,99124363.3 Chinese patent such as grade, and these technology only have single channel monitoring function.Its channel monitoring device generally comprises array waveguide grating (AWG) device, optical power detector array and conversion of signals and processing unit etc.As shown in Figure 1, be its a kind of embodiment, it is combined into one road multi-wavelength signals with the signal of multichannel different wave length through AWG 1, through tap coupler (TAP) 2, part luminous power according to a certain percentage is incorporated in the channel monitoring device 8, after having array waveguide grating (AWG) 3 that light signal is decomposed into the signal of multichannel different wave length in this device 8 again, by 4 receptions of optical power detector array (PINARRAY), pass through signal amplifier 5, analog to digital converter 6 and data processor 7 again, can obtain relevant channel power, signal to noise ratio and wavelength etc. for information about.The weak point of said system is to need two array waveguide gratings (AWG), and system configuration is comparatively complicated, and cost is higher, the more important thing is owing to there are two AWG to produce performance difference unavoidably, and causes measurement accuracy and reliability lower.

Summary of the invention: the invention is merged into one with two AWG at the shortcoming of prior art in the WDM optical transmission system, realize existing splitting/composing wave energy, and the purpose of channel monitoring function is arranged again.

For achieving the above object, the technical scheme of the invention be will existing two array waveguide grating AWG 1 and the function of building blocks of functions such as AWG 3, tap coupler 2, optical power detector 4 substitute by a wave splitting/composing, channel monitoring assembly 11, structure such as other signal amplifiers, A/D converter and data processor and annexation thereof are constant.This wave splitting/composing, the channel monitoring assembly is the centre point of the invention, its design feature is that a signal that can either one road multiple wavelength optical signal be decomposed into the multichannel different wave length is arranged, multichannel different wave length light signal can be synthesized the AWG wave splitting/composing device of one road multi-wavelength signals again, its output waveguide surrounding layer has thinning area, in thinning area coupling piece is installed, optical power detector is housed on the coupling piece, optical power detector and coupling piece end face are angled, the installation site requires each optical power detector induction zone to aim at corresponding output waveguide, input-output optical fiber is set then, temperature conditioning unit and power detector array draw electrical interface, encapsulation forms to package shell again.

The invention has the beneficial effects as follows that the function with AWG wave splitting/composing device and AWG channel monitoring device combines, become a kind of device of comprehensive function, make that channel monitoring function becomes more simple in the wdm system, measure more accurately and reliably, and simplify the structure, reduced cost.

Description of drawings:

Fig. 1 is the line principle schematic diagram of a kind of embodiment of existing channel supervising device in the wdm system;

Fig. 2 is a line principle block diagram of the present invention, and the centre point of invention is exactly the wave splitting/composing shown in the figure, channel monitoring assembly;

Fig. 3 is the schematic diagram of a kind of embodiment of wave splitting/composing among Fig. 2, channel monitoring assembly;

Fig. 4 represents that the vitals in wave splitting/composing, the channel monitoring assembly promptly utilizes the high index of refraction coupling piece part energy in the waveguide to be coupled into the schematic diagram of a kind of embodiment of optical power detector array.

Embodiment:

Can further understand the execution mode of technical solution of the present invention by the reference accompanying drawing.From Fig. 2, the utilization of this device as can be seen in module, has been simplified the structure of system with the function synthesized of original two modules, has realized higher integrated of subsystem, meets the development trend of modern optical communication device.Wave splitting/composing channel monitoring assembly 11 is with wave splitting/composing and channel monitoring function among Fig. 2, this assembly is when finishing the splitting/composing wave energy, the part luminous power is coupled on the optical power detector array that is installed in wherein, realized changing light signal into the signal of telecommunication, and this signal of telecommunication is applied on the signal amplification unit 5, is converted into digital signal through amplifying signal by A/D converting unit 6.Digital signal is through the processing of data processing unit 7, and its result is output to other processing units of system.Realized supervision like this to all wavelengths signal.

Fig. 3 shows a kind of embodiment of the wave splitting/composing assembly 11 that has channel monitoring function.The waveguide of common AWG comprises one or more input waveguides arranged side by side 14, and the multiplex signal that is used for mixing a plurality of wavelength channel 1 to λ n propagates into first waveguide zone 15, and waveguide zone is a star-like coupled zone or other zone similarity.Waveguide zone 15 links to each other with Waveguide array district 16, and input signal is distributed to the many waveguides in Waveguide array district, and these waveguides constitute gratings.Each root waveguide all has different optical lengths, and the optical length of adjacent waveguide is according to a steady state value relevant with centre wavelength increase and decrease, and the waveguide length from a side of grating to opposite side progressively increases progressively.What link to each other with the Waveguide array other end is another waveguide zone 17, the interference of being introduced by waveguide array grating district 16 that relative phase difference caused can occur in second waveguide zone 17.The chromatic dispersion of waveguide optical grating physically separates the different wave length of flashlight, and focuses on the output plane of second waveguide zone 17, and the wavelength that separates is coupled in a plurality of output waveguides that link to each other with second waveguide zone 17.The output signal of different centre wavelengths is corresponding to different output waveguides 18 positions, thereby realized function that the different wave length signal is separated from the space.Utilize the reciprocal principle of light path, array waveguide grating had both had the multiplexing function of multiple wavelength optical signal and had also had the function of multiple wavelength optical signal demultiplexing.The centre wavelength of each wavelength channel and interval are depended on the geometry of AWG waveguide and are formed the effective refractive index of the Waveguide array of grating.In order to obtain the luminous power size of each wavelength channel, the installation site of optical power detecting array generally be in the output waveguide array directly over, as shown in Figure 3.The spacing of necessary selective light power detector array is consistent with the spacing of output waveguide array, and each optical power detector must be aimed at corresponding output waveguide, can obtain the exact value of each wavelength channel luminous power like this.The coupling piece that has detector array is installed in the relevant position of output waveguide, draws the electrical interface of input optical fibre 12, output optical fibre 20, temperature conditioning unit and optical power detector array then.Pass through means such as shell encapsulation then, made the partial wave assembly that has channel monitoring function at last.

Fig. 4 has shown a kind of application example that utilizes the high index of refraction coupling piece part energy in the waveguide to be coupled into optical power detector array 4.The integrated light guide of forming array waveguide optical grating generally is made up of three layers of dielectric medium structure, its at the middle and upper levels 22 and lower floor 24 be low-index layer, the centre is the higher sandwich layer of refractive index 23, the overwhelming majority light energies all be constrained in the sandwich layer.For the portion of energy with light is coupled out, need to destroy original complete three-decker from sandwich layer.Therefore the structure of the top covering 22 of waveguide is carried out attenuate, attenuate can utilize dry method and two kinds of methods of wet etching.On original waveguiding structure, just formed a thinning area 19 like this, in order the splitting/composing wave energy not to be brought too many loss, attenuate to the output waveguide top covering can not be corrupted in sandwich layer 23 structures, and generally selecting the remaining thickness of top covering is between 0～6 micron.The structural parameters of coupling piece 21 and the selection of refractive index all are vital for the power of the luminous power that the loss and the detector of device receives.In the preference that we implement, the refractive index of selection coupling piece exceeds the refractive index of top covering slightly, and coupling piece length is selected shortly as far as possible, and thickness is greater than the length of detector array sensitive surface 25.The installation of detector array electrical lead for convenience and reach better reception, the end face of detector array and coupling piece is angled.The coupling piece process that is equipped with detector array is aimed at the thinning area that is placed on the output waveguide top covering, and the ultraviolet cured adhesive of selective refraction rate coupling is fixed coupling piece and array waveguide grid chip.In the past surface analysis as can be seen the effect of the coupling piece 21 of high index of refraction be to connect the output waveguide 18 of detector array 4 and array waveguide grating and the portion of energy in the waveguide core layer 22 is coupled in the detector array; If the ultra-violet curing glue of selecting for use a kind of refractive index to be fit to, after ultra-violet curing glue is cured, between output waveguide 18 and detector array 4, can form one deck and have ultraviolet glue coupling layer with coupling piece 21 said functions, be equal to so the structure of this structure and installation coupling piece can be considered.

Claims

1, a kind of Waveguide grating array wave splitting/composing device that channel monitoring function is arranged, it comprises array waveguide grating (AWG), coupling piece, optical power detector, signal amplifier, A/D converter and data processor, it is characterized in that having the surrounding layer of its output waveguide of AWG wave splitting/composing device that thinning area is arranged, in thinning area coupling piece is installed, optical power detector is installed on the coupling piece, and the optical power detector induction zone should be aimed at corresponding output waveguide.

2, by the described device of claim 1, it is characterized in that output waveguide is made up of three layers of dielectric medium structure, upper strata (22), lower floor (24) is low-index layer, intermediate layer (23) is the higher sandwich layer of refractive index, the energy constraint of most of light is in sandwich layer, there is thinning area (19) on waveguide upper strata (22), thinning area lower surface to the thickness of sandwich layer upper surface is 0～6 micron, select the refractive index of the refractive index of coupling piece (21) a little more than top covering, coupling piece length is selected short, thickness is slightly larger than the length of detector array sensitive surface (25), detector array (4) is angled with coupling piece (21) end face, the coupling piece aligning that is equipped with detector array is placed on the thinning area (19) that output waveguide (18) goes up the ripple layer, adopts the ultraviolet glue of refractive index match to fix between coupling piece and the array waveguide grid chip.

3,, it is characterized in that coupling piece (21) connects the output waveguide (18) of detector array (4) and array waveguide grating, can substitute with the ultra-violet curing glue of refractive index match by the described device of claim 1.