CN201069475Y - Spectrum flatting single-fiber three-folded wave division multiplexer - Google Patents

Abstract

The utility model discloses a single-fiber wave division triplexer planarized frequency spectrum, which comprise, in ordered connection, a input waveguide, a input planar waveguide zone, an array waveguide zone, an output planar waveguide zone, three output waveguides correspondent to optical signal outputs with wavelengths of 1310 nm, 1490 nm and 1550 nm respectively, and a frequency spectrum planarization structure arranged between each output waveguide and the output planar waveguide zone. The frequency spectrum planarization structure may be multi-mode interference waveguide, parabolic-type waveguide or Y branch. The utility model realizes the single-fiber wave division triplexer planarized frequency spectrum with large design freedom, can optimize the planarization of frequency spectrum for each output channel, and can efficiently increase the 3dB bandwidth of spectral response of each signal channel.

Description

The single-fiber triple wavelength division multiplexer of flattened spectral response

Technical field

The utility model relates to wavelength division multiplexer, relates in particular to a kind of single-fiber triple wavelength division multiplexer of flattened spectral response.

Background technology

Remove backbone network and Metropolitan Area Network (MAN), the important development Construction Party of Access Network becomes gradually optical communication that Fiber to the home to.Fiber to the home (FTTH) can provide profuse bandwidth to the user, is a kind of desirable access module, is that Future Optical Fibre Communication Systems solves the best way of " last kilometer ", and will becomes the sign of new generation broadband network.Eleventh Five-Year Plan clearly proposes: " strengthen information infrastructure buildings such as broadband communication network, digital tv network and Next Generation Internet, advance the integration of three networks ".The integration of three networks is to replace present voice, data and three networks of video with a network, and integrates the function of three networks.Adopt the single fiber three-way transmission technology to realize a main flow of the transmission of this integrated service technical development that become gradually that Fiber to the home.This sun adjuster spare has proposed new technical requirement and has opened up a brand-new application for it.

In Fiber to the home access net system, single-fiber three-way multiplexer (Triplexer) is a kind of essential basic components and parts.Launch the light signal (data service 1490nm, video traffic 1550nm) of two different wave lengths (1490nm/1550nm) from central control unit.This two paths of signals is opened by the Triplexer branch after sending to terminal via an optical fiber, is coupled to a digit signal receiver (data service 1490nm) and a receiver of the analog signal (video traffic 1550nm) then respectively.Light signal (speech business 1310nm) with a digital signal projector emission is coupled to same optical fiber reverse transfer to central control unit by Triplexer simultaneously.With respect to other discrete type device, has the integrated level height, outstanding advantages such as size is little, stability is high, production in enormous quantities based on the Triplexer of array waveguide grating (AWG).The structure of common AWG single-fiber triple wavelength division multiplexer comprises an input waveguide, input waveguide zone, Waveguide array district, output waveguide zone and three output waveguides of linking to each other successively as shown in Figure 1.Light is transmitted to output waveguide by input waveguide zone, Waveguide array district and output waveguide zone successively from input waveguide.Article three, output waveguide respectively corresponding wavelength be 1310nm, the output of the light signal of 1490nm and 1550nm.

In WDM (wavelength-division multiplex) system, the channel bandwidth of device is one of its key property.Shape by spectral response can be divided into the AWG wavelength division multiplexer Gaussian and flat-head type.For Gaussian AWG wavelength division multiplexer, because its 1dB bandwidth is less, the influence of extraneous factor (as the working temperature drift etc.) has limited the application of device in system greatly.By contrast, the 1dB bandwidth of flat-head type AWG wavelength division multiplexer is much bigger, thereby has lot of advantages: (1) allows High Speed Modulation; Allow the emission wavelength of laser instrument that skew is in a small amount arranged; Reduced susceptibility to temperature variation; Reduced susceptibility to polarization; Reduced refractive index control accuracy requirement etc. in the technology.Therefore, thus by adopting the flattened spectral response structure to realize that flat-head type AWG wavelength division multiplexer is a gordian technique.

The existing multiple method that is used for AWG wavelength division multiplexer flattened spectral response.For example document " Flat channelpassband wavelength multiplexing and demultiplexing devices by multiple Rowlandcircle design; " Y.P.Ho, H.Li and Y.J.Chen, IEEE Photo.Technol.Lett., 9 (3): 342-344, mention in 1997 and can use two rowland structures.Document " Multigrating method for flattenedspectral response wavelength multi/demultiplexer; " Rigny.A., A.Bruno and H.Sik., Electron.Lett., 33 (20): 1701-1702, mention in 1997 and can use the double grating structure.

Document " Compact and low-loss integrated box-like passband multiplexer; " C.R.Doerr, L.W.Stulz, and R.Pafchek, IEEE Photo.Technol.Lett., 15 (7): 918-920,2003 propose to utilize the method for Mach-Ze De interferometer (MZI) and AWG cascade: design MZI Free Spectral Range (FSR) makes it to equate with the AWG channel spacing.At this moment, on the AWG input face, produce different precompiles behind the logical interior wavelength process MZI of band, thereby the image space in output face nearly all is in the center of output waveguide, thereby the output of the logical interior wavelength of band much at one, promptly realized flattened spectral response.

A kind of easy method directly perceived is to connect special flattened spectral response structure in I/O waveguide place.For example at United States Patent (USP) C.Dragone and L.Siliver, US patent.No.5,706,377, Feb/1995 proposes and can connect Y branch in I/O waveguide place; And document " Flat spectral responsearrayed-waveguide grating multiplexer with parabolic waveguide homs; " K.Okamoto and A.Sugita, Electron.Lett., 32 (18): 1661-1662 proposes introducing parabolical waveguide between input waveguide and input waveguide zone in 1996; Document " Use of multimode interferencecouplers to broaden the passband of wavelength-dispersive integrated WDM filters; " J.B.D.Soole, et al, IEEE Photo.Technol.Lett., 8 (10): 1340-1342, propose between input waveguide and input waveguide zone, to introduce standard multi-module interference coupler (Multimode interferencecoupler is called for short MMI) in 1996.

Similarly, common AWG Triplexer has the Gaussian spectral response, and its 1dB bandwidth is less than 10nm.In order further to reduce element manufacturing and packaging cost (for example cancelling attemperating unit), be necessary to adopt the flattened spectral response design fully.Different with common AWG wavelength division multiplexer is: the operating wavelength range of Triplexer is big (1310nm～1550nm is greater than 240nm) very, and the operating wavelength range of common AWG wavelength division multiplexer only is about 30nm usually.In common AWG wavelength division multiplexer flattened spectral response structural design, often only need to design at AWG central passage wavelength.Yet this design also is not suitable for the flattened spectral response of Triplexer.

Summary of the invention

The purpose of this utility model is at the deficiencies in the prior art, proposes a kind of single-fiber triple wavelength division multiplexer of flattened spectral response, is Gaussian to solve common single-fiber triple wavelength division multiplexer spectral response, the problem that passage three dB bandwidth is little.

The purpose of this utility model is achieved through the following technical solutions: the single-fiber triple wavelength division multiplexer of flattened spectral response comprises an input waveguide that links to each other successively, the input waveguide zone, the Waveguide array district, output waveguide zone and three output waveguides, article three, output waveguide respectively corresponding wavelength be 1310nm, the light signal output of 1490nm and 1550nm is characterized in that connecting the flattened spectral response structure between every output waveguide and output waveguide zone.

Above-mentioned flattened spectral response structure can be multiple-mode interfence waveguide, parabolic type waveguide or Y branch.

The utility model inserts the flattened spectral response structure between output waveguide and output waveguide zone, can make the wavelength in each channel center's wavelength neighborhood all have almost equal output power, has promptly realized flattened spectral response.

The beneficial effects of the utility model are:

1. the utility model adopts in every output waveguide and output planar waveguide and inserts the flattened spectral response structure, and principle of work is simple, can realize the single-fiber triple wavelength division multiplexer of flat-head type.

2. the single-fiber triple wavelength division multiplexer of flattened spectral response of the present utility model, the parameter of each flattened spectral response structure can design at channel center's wavelength separately, has very big design freedom, can all obtain optimized flattened spectral response effect to each output channel, can all bring up to the three dB bandwidth of each output channel about 20nm, especially reduced the susceptibility of device to wave length shift, thereby make device more reliable in actual applications, also reduced the use cost of device.

3. the single-fiber triple wavelength division multiplexer of flattened spectral response of the present utility model and traditional array waveguide optical grating manufacture craft are compatible fully, do not need additional technical steps, have that structural design is simple, manufacture craft simple, low cost and other advantages.

Description of drawings

Fig. 1 is the structural representation of common AWG single-fiber triple wavelength division multiplexer;

Fig. 2 is the structural representation of the single-fiber triple wavelength division multiplexer of flattened spectral response of the present utility model;

Fig. 3 is the spectral response analog result figure of each bar output waveguide of single-fiber triple wavelength division multiplexer of embodiment 1;

Fig. 4 is the spectral response analog result figure of each bar output waveguide of single-fiber triple wavelength division multiplexer of embodiment 2;

Fig. 5 is the Y branch flattened spectral response structural representation among the embodiment 3;

Fig. 6 is the spectral response analog result figure of each bar output waveguide of single-fiber triple wavelength division multiplexer of embodiment 3.

Embodiment

The utility model is described in further detail below in conjunction with drawings and Examples.

With reference to Fig. 2, the single-fiber triple wavelength division multiplexer of flattened spectral response of the present utility model, comprise an input waveguide 1 that links to each other successively, input waveguide zone 2, Waveguide array district 3, output waveguide zone 4 and 5, three output waveguides of three output waveguides corresponding wavelength respectively are 1310nm, the light signal output of 1490nm and 1550nm connects flattened spectral response structure 6 between every output waveguide 5 and output waveguide zone 4.

Flattened spectral response structure in the utility model can be multiple-mode interfence waveguide, parabolic type waveguide or Y branch.By adopting the flattened spectral response structure of different parameters, can make that the wavelength in each channel center's wavelength neighborhood all has almost equal output power, realize flattened spectral response.

Embodiment 1 flattened spectral response structure is multiple-mode interfence (MMI) waveguide

Multiple-mode interfence (MMI) waveguide of adopting is that refringence is the 6 μ m * 6 μ m SiO of Δ=0.75% ₂-on-Si buries the type optical waveguide, and the parameter of mmi waveguide is as follows:

	Article one, output waveguide	The second output waveguide	Article three, output waveguide
				Centre wavelength (nm)	1490	1310	1550
MMI width W (μ m)	13.8	12.6	14.4
				MMI length L (μ m)	150	141	154

Fig. 3 is the spectral response analog result of this example based on each bar output waveguide in the flattened spectral response single-fiber triple wavelength division multiplexer of multiple-mode interfence (MMI) waveguide.Among the figure, the three dB bandwidth of first, second, third output waveguide spectral response is respectively 24nm, 28nm, 30nm.This shows, adopt the utility model can realize flattened spectral response.

Embodiment 2 flattened spectral response structures are the parabolic type waveguide

The parabolic type waveguide shapes is given by formula: $w=W\sqrt{1-z/L},$ Z is for to enter the mouth to the distance of end direction from the parabolical waveguide in the formula, and L is the parabolical waveguide length, and W is the parabolical duct width.The parabolic type waveguide of adopting is that refringence is the 6 μ m * 6 μ m SiO of Δ=0.75% ₂-on-Si buries the type optical waveguide, and the parabolic type waveguide parameter is as follows:

	Article one, output waveguide	The second output waveguide	Article three, output waveguide
				Centre wavelength (nm)	1490	1310	1550
Width W (μ m)	24	22.5	25
				Length L (μ m)	300	296	305

Fig. 4 is the spectral response analog result of this example based on each bar output waveguide in the flattened spectral response single-fiber triple wavelength division multiplexer of parabolic type waveguide.Among the figure, the three dB bandwidth of first, second, third output waveguide spectral response is respectively 36nm, 37nm, 38nm.This shows, adopt the utility model to realize flattened spectral response.

Embodiment 3 flattened spectral response structures are Y branch

Fig. 5 is the Y branched structure that is adopted, and G is the gap length between the Y branch among the figure, and L is the gap lengths between the Y branch, L _TpBe tapered transmission line length.

Tapered transmission line shape in the Y branched structure is given by formula: $w=W\sqrt{1-z/L}.$ Z is for to enter the mouth to the distance of end direction from the parabolical waveguide in the formula, and L is a tapered transmission line length, and W is the tapered transmission line width.

The employing refringence is the 6 μ m * 6 μ m SiO of Δ=0.75% ₂-on-Si buries the type optical waveguide, and then the Y branch parameter is as follows:

	Article one, output waveguide	The second output waveguide	Article three, output waveguide
				Centre wavelength (nm)	1490	1310	1550
Space G (μ m)	2	2	2.4
				Length L (μ m)	50	50	50
The tapered transmission line length L tp (μm)	220	235	240

Fig. 6 is the spectral response analog result of this example based on each bar output waveguide in the flattened spectral response single-fiber triple wavelength division multiplexer of Y branch.Among the figure, the three dB bandwidth of first, second, third output waveguide spectral response is respectively 24nm, 24nm, 25nm.This shows, adopt the utility model can realize flattened spectral response.

The foregoing description is used for the utility model of explaining; rather than the utility model limited; in the protection domain of spirit of the present utility model and claim, any modification and change to the utility model is made all fall into protection domain of the present utility model.

Claims (4)

1. the single-fiber triple wavelength division multiplexer of flattened spectral response, comprise an input waveguide (1) that links to each other successively, input waveguide zone (2), Waveguide array district (3), output waveguide zone (4) and three output waveguides (5), article three, output waveguide respectively corresponding wavelength be 1310nm, the output of the light signal of 1490nm and 1550nm is characterized in that connection flattened spectral response structure (6) between every output waveguide (5) and output waveguide zone (4).

2. the single-fiber triple wavelength division multiplexer of flattened spectral response according to claim 1 is characterized in that said flattened spectral response structure (6) is a multi-mode interference coupler.

3. the single-fiber triple wavelength division multiplexer of flattened spectral response according to claim 1 is characterized in that said flattened spectral response structure (6) is the parabolic type waveguide.

4. the single-fiber triple wavelength division multiplexer of flattened spectral response according to claim 1 is characterized in that said flattened spectral response structure (6) is a Y branch.

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