2 * 2 polarization maintaining optical fibre beam splitters
Technical field
The utility model relates to a kind of Passive Optical Components of realizing the luminous power beam splitting, particularly a kind of 2 * 2 polarization maintaining optical fibre beam splitters that can keep optical polarization, it can be applied to optical fibre gyro, fibre optic hydrophone and other sensory field of optic fibre and fiber optic communication field.
Background technology
Fiber coupler (Coupler) is to divide element in the bar optical fiber at the most with light signal from an optical fiber, belongs to a kind of optical passive component, is widely used in fields such as optical communication network, cable TV networks.Polarization maintaining optical fibre is the optical fiber that can keep original polarization state transmission of light wave, in interferometric optical fiber sensor based on the optical coherence detection, use polarization maintaining optical fibre can keep the polarization direction of light wave constant, improve relevant signal to noise ratio, to realize high-acruracy survey physical quantity.
The method of existing making general single mode fiber coupling mechanism all adopts fiber fuse to draw the awl scheme, for the ordinary optic fibre coupling mechanism, and can be referring to Chinese patent:
1, makes the method for fiber coupler, application number 91110661.8;
2, the manufacture method of fiber coupler, application number 92100774.4;
3, fiber coupler and manufacture method thereof, application number are 93102327.0;
4, fiber coupler, its manufacture method and manufacturing equipment thereof ", application number 01122161.5.
For polarization-maintaining fiber coupler, can be referring to Chinese patent
1, automated fused biconical taper device for polarization maintaining fiber coupler ", application number 200510032378.0;
2, the manufacture method of polarization-maintaining fiber coupler, application number 200610063123.5;
3, polarization-maintaining fiber coupler, its preparation method and all-fiber current sensor ", application number 200810043138.4.
The ultimata of above-mentioned these schemes all is to adopt fiber fuse to draw the awl scheme, this scheme more is applicable to the drawing general single mode fiber, has the yield rate height, low cost and other advantages, but for polarization maintaining optical fibre, the crucial problem that needs to solve Stress Profile for Polarization-Maintaining axle aligning, the weakness that the inherent stress axle of these schemes own can't be aimed at, the poor-performing that causes the polarization-maintaining fiber coupler of this scheme making, during as the drawing coupling mechanism, polarization maintaining optical fibre is by drawing-down, stress area changes, cause polarization extinction ratio not high, temperature performance instability, weakness such as operating wavelength range is narrow; Adopt the ratio defective product of this scheme lower in addition, repeatedly doing over again to cause the starting material polarization maintaining optical fibre can not satisfy length requirement, causes cost higher.
The technical scheme that the utility model proposed is to adopt glass bushing technology, by the stress axis direction of aiming at polarization maintaining optical fibre at microscopically, through being made into polarization maintaining fiber pigtail behind end face polishing, the plating anti-reflection film; It is to realize the luminous power beam splitting by optical medium film, the power of light wave is divided into 2 parts, it sees through with the ratio that reflects and can realize by deielectric-coating, as semi-transparent semi-reflecting film, utilize the assembling that is coupled of glass bushing technology then, function and the polarization-maintaining fiber coupler realized are identical, only the Physical Mechanism difference of Shi Xianing, therefore the utility model name is called " polarization maintaining optical fibre beam splitter "
In addition, existing 2 * 2 fiber couplers, its optical fiber pigtail type be optical fiber of the same race, tail optical fiber is ordinary optic fibre, be polarization maintaining optical fibre, this situation makes the scope of application of fiber coupler become narrow, all adopts ordinary optic fibre, cheap for manufacturing cost, but polarization keeps performance to reduce; All adopt polarization maintaining optical fibre, though polarization keeps performance to improve, manufacturing cost also increases thereupon, and yield rate reduces; If adopt the scheme of mixing tail optical fiber, can make the scope of application of fiber coupler more extensive, and reach optimized application.
The utility model content
Technical problem to be solved in the utility model provides a kind of 2 * 2 polarization maintaining optical fibre beam splitters, its function that realizes is identical with the polarization-maintaining fiber coupler that adopts the fused biconical taper method to make, and temperature performance is stable, polarization extinction ratio is high, and operating wavelength range is big.
For solving the problems of the technologies described above, the utility model is realized as follows: 2 * 2 polarization maintaining optical fibre beam splitters described in the utility model are made up of big glass tube, input end cuvette, output terminal cuvette, input end glass capillary, output terminal glass capillary, input end twin-core fiber tail optical fiber, output terminal twin-core fiber tail optical fiber, input end lens and output terminal lens; Big glass tube two ends connect input end cuvette and output terminal cuvette respectively, and they bond fixing by optical cement; Input end and output terminal in big glass tube inboard are respectively equipped with input end lens and output terminal lens, and lens are fixing with big glass tube bonding by optical cement; Be with input end glass capillary and output terminal glass capillary in input end cuvette and the output terminal cuvette respectively, and fixing by the glass cement bonding; The merging end of input end twin-core fiber tail optical fiber and output terminal optical fiber pigtail is fixed in input end glass capillary and the output terminal glass capillary with glue respectively vertically.
Described input end lens and output terminal lens are GRIN Lens, input end lensed endface evaporation Tap film, 0.25Pitch; Output terminal lensed endface evaporation anti-reflection film, 0.23Pitch.Wherein, the Tap film is for having partial reflection, the optical coating of part transmission function; Pitch refers to 1 Cycle Length of GRIN Lens.
Described input end lens and output terminal lens are C type lens, C type lensed endface plating anti-reflection film, and in the middle of input end lens and output terminal lens, big glass tube inwall is provided with deielectric-coating catoptron carrier, and evaporation has the deielectric-coating catoptron on the deielectric-coating catoptron carrier.
Described input end twin-core fiber tail optical fiber and output terminal twin-core fiber tail optical fiber are at the microscopically dead axle, and the dead axle mode is the parallel or stress area serial of stress area.
Described input end twin-core fiber tail optical fiber and output terminal twin-core fiber tail optical fiber are aimed at " eight " font, to eliminate FP (Fabry-Perot) effect.
Two of described input end twin-core fiber tail optical fiber is respectively tail optical fiber A and tail optical fiber B, and two of output terminal twin-core fiber tail optical fiber is respectively tail optical fiber C and tail optical fiber D; Tail optical fiber A, tail optical fiber B, tail optical fiber C and tail optical fiber D are respectively general single mode fiber or polarization maintaining optical fibre.
Good effect of the present utility model is: this beam splitter adopts glass bushing technology, by aim at the stress axis direction of polarization maintaining optical fibre at microscopically, through being made into polarization maintaining fiber pigtail behind end face polishing, the plating anti-reflection film, utilize the assembling that is coupled of glass bushing technology then, wherein tail optical fiber also can select single-mode fiber to make up, and forms the structure of partly protecting inclined to one side semisimple module optical fiber; Wherein the power beam splitter can adopt the coating process of Thin Film Filter to realize the splitting ratio of required making, perhaps direct end face evaporation luminous power beam splitting dielectric film in GRIN Lens; Technology is simple, and is stable, dependable performance; Because the dielectric film operation wavelength bandwidth of evaporation can reach 100nm, therefore have the characteristics in broadband, also have the yield rate height, it is little to insert loss, and operating temperature range is wide, short (<27mm) the advantage of total length.In addition, the polarization-maintaining coupler that fused biconical taper is made, the stress direction of polarization maintaining optical fibre are merely able to the optical fiber dead axle mode that adopts stress area parallel, because optical fiber is elongated, the stressed zone weakens, so the polarization hold facility dies down relatively; This polarization-maintaining beam splitter carries out the optical fiber dead axle at microscopically, therefore not only can adopt the parallel optical fiber dead axle mode of stress area, and can adopt the optical fiber dead axle mode of stress area serial, thereby strengthens stress distribution, improves polarization maintaining properties.
Description of drawings
Below in conjunction with the drawings and specific embodiments the utility model is described in further detail.
Fig. 1 is the utility model 2 * 2 polarization maintaining optical fibre beam splitter cross-sectional view
Fig. 2 is another embodiment cross-sectional view of the utility model
Fig. 3 is the parallel optical fiber dead axle mode of stress area
Fig. 4 is the optical fiber dead axle mode of stress area serial
1 big glass tube 2 input end cuvettes 3 output terminal cuvettes among the figure
4 input end glass capillaries, 5 output terminal glass capillaries
6 input end twin-core fiber tail optical fibers, 7 output terminal twin-core fiber tail optical fibers
8 input end lens, 9 output terminal lens, 10 optical cements
11 deielectric-coating catoptron carrier 12 deielectric-coating catoptrons
13 tail optical fiber A, 14 tail optical fiber B, 15 tail optical fiber C, 16 tail optical fiber D
Embodiment
Be illustrated in figure 1 as a kind of embodiment of 2 * 2 polarization maintaining optical fibre beam splitters described in the utility model, it is made up of big glass tube 1, input end cuvette 2, output terminal cuvette 3, input end glass capillary 4, output terminal glass capillary 5, input end twin-core fiber tail optical fiber 6, output terminal twin-core fiber tail optical fiber 7, input end lens 8 and output terminal lens 9; Big glass tube 1 two ends connect input end cuvette 2 and output terminal cuvette 3 respectively, and they bond fixing by optical cement 10; Input end and output terminal in big glass tube 1 inboard are respectively equipped with input end lens 8 and output terminal lens 9, and lens are fixing with big glass tube 1 bonding by optical cement 10; Be with input end glass capillary 5 and output terminal glass capillary 6 in input end cuvette 2 and the output terminal cuvette 3 respectively, and fixing by glass cement 10 bondings; The merging end of input end twin-core fiber tail optical fiber 6 and output terminal optical fiber pigtail 7 is fixed in input end glass capillary 5 and the output terminal glass capillary 6 with glue respectively vertically.
Described input end lens 8 and output terminal lens 9 are GRIN Lens, input end lens 8 end face evaporation Tap films, 0.25Pitch; Output terminal lens 9 end face evaporation anti-reflection films, 0.23Pitch.
Fig. 2 is another embodiment of the present utility model, also can be C type lens for described input end lens 8 of the foregoing description and output terminal lens 9, C type lensed endface plating anti-reflection film, under the situation that adopts C type lens, in the middle of input end lens 8 and output terminal lens 9, big glass tube 1 inwall is provided with deielectric-coating catoptron carrier 11, and evaporation has deielectric-coating catoptron 12 on the deielectric-coating catoptron carrier 11, to improve the polarization extinction ratio of system.
Described input end twin-core fiber tail optical fiber 6 and output terminal twin-core fiber tail optical fiber 7 are at the microscopically dead axle, and the dead axle mode is that stress area is parallel, referring to Fig. 3; Or the stress area serial, referring to Fig. 4.
Described input end twin-core fiber tail optical fiber 6 and output terminal twin-core fiber tail optical fiber 7 are aimed at " eight " font, to eliminate the FP effect.
Two of described input end twin-core fiber tail optical fiber 6 is respectively tail optical fiber A 13 and tail optical fiber B 14, and two of output terminal twin-core fiber tail optical fiber 7 is respectively tail optical fiber C 15 and tail optical fiber D 16; Tail optical fiber A 13, tail optical fiber B 14, tail optical fiber C 15 and tail optical fiber D 16 are respectively general single mode fiber or polarization maintaining optical fibre.
Specifically, the optical fiber selection scheme of tail optical fiber, the pairing of the optical fiber that can select is as follows:
1, A, B, C, D end all are polarization maintaining optical fibres.
2, A, B, C, D end all are general single mode fibers.
3, A, B end is a polarization maintaining optical fibre, and C, D end is a single-mode fiber; Perhaps A, B end is a single-mode fiber, and C, D end is a polarization maintaining optical fibre; Polarization maintaining optical fibre reflexes in the polarization maintaining optical fibre, is transmitted in the single-mode fiber.
4, A, D end is a polarization maintaining optical fibre, and B, C end is a single-mode fiber; Perhaps A, D end is a single-mode fiber, and B, C end is a polarization maintaining optical fibre; When being coupled and aligned, can select polarization maintaining optical fibre to be transmitted in the polarization maintaining optical fibre, reflex in the single-mode fiber; Perhaps polarization maintaining optical fibre is transmitted in the single-mode fiber, reflexes in the polarization maintaining optical fibre.
5, the array mode of other polarization maintaining optical fibres and single-mode fiber.
If adopting 2 optical fiber of an end all is polarization maintaining optical fibre, 2 optical fiber of an other end all are single-mode fibers, the input of realization polarization maintaining optical fibre, protective eccentric reflective, the characteristics of single mode transmission are used for sensory field of optic fibre, not only can improve the temperature stability of sensor-based system, and can reduce device cost, reduce the technology difficulty of element manufacturing.If adopting one of 2 optical fiber of an end is polarization maintaining optical fibre, other one is single-mode fiber; Same one of 2 optical fiber of an other end are polarization maintaining optical fibres, and other one is single-mode fiber; The input of realization polarization maintaining optical fibre, the polarization maintaining optical fibre transmission, the characteristics of single-mode fiber reflection are used for sensory field of optic fibre, under the temperature stability prerequisite that improves sensor-based system, can realize reducing device cost equally, reduce the characteristics of the technology difficulty of element manufacturing.