A kind of packaging system of fiber grating
Technical field
The present invention relates to the fiber grating encapsulation technology, particularly can carry out the packaging system of temperature compensation and tuning fiber grating.
Background technology
Fiber grating is to it is found that the full optical fibre device that develops rapidly behind the light sensitive characteristic of grating.Ultraviolet ray irradiation light-sensitive optical fibre can make optical fibre refractivity generation permanent change, according to this effect fibre core is periodically exposed, thereby obtains fiber grating.It has, and the reflection bandwidth scope is big, and added losses are little, and volume is little, and device miniatureization can well be coupled with optical fiber, can be integral with other optical fibre device compatibilities, a series of excellent properties such as be not subjected to that environment dust influences.Use fiber grating to can be made into Wavelength division multiplexer/demultiplexer, fiber laser, Distributed Feedback Laser, wave filter, wave filter, the contour performance optic communication device of dispersion compensator.Fiber grating can be divided into two classes, and a class is called mode transmission or long-period gratings (being called for short LPG), and the refractive index cycle modulation will cause the coupling between equidirectional transmission mode; Another kind of reflection-type or the short period fiber grating of being called also claims Fiber Bragg Grating FBG (being called for short FBG), and the refractive index cycle modulation will cause the coupling between the reverse direction transmission mode.When the light wavelength of transmitting in optical fiber satisfied Bragg condition, because the interference of light effect, its reflectivity approached 100%.The appearance of fiber grating has brought a revolution to optical fiber communication and optical fiber sensing technology.
The length of high-quality fiber grating that is used for dispersion compensation is generally longer, its foveal reflex wavelength can drift about with the fluctuation of environment, and grating is long more, its reflectance spectrum is subjected to Temperature Influence long more, the coarse dispersion compensation that causes thus will cause the deterioration of system performance, hinders the practicability of fiber grating.Therefore need control the environment temperature of the fiber grating of practicability, just will carry out temperature compensation fiber grating.The temperature compensation of fiber grating specifically can be divided into two classes: one, and passive mode promptly encapsulates fiber grating with suitable structure and material, and encapsulation makes grating produce certain strain.Existing optical fiber grating temperature compensation method is a kind of to be the encapsulating material that utilizes two kinds of different heat expansion coefficients, when temperature changes, length variations by encapsulating material changes the tension force that is applied to the fiber grating two ends makes it to offset influence by variations in refractive index, thereby reaches the effect of temperature compensation.US Patent No 5042898, No 5841920 grades have provided the encapsulating material that utilizes two kinds of different expansion coefficient carries out temperature compensation to fiber grating method.Another kind is the method for fiber grating being carried out temperature compensation with the material with negative thermal expansion coefficient, as US Patent No 5694503.
In modern optical fiber telecommunications system, tunable the seeming of fiber optic telecommunications equipment more and more reuses, and several tuning devices of realization strain commonly used comprise:
1, existing fiber grating tuning method comprises temperature control method (US Patent No 5987200, US Patent No 6181852).
2, magnetostrictive tuning device: this device comprises a fiber grating, one section magnetostriction materials and solenoid.Fiber grating sticks on the magnetostriction materials side, the solenoid cover outside, the magnetic field of portion's generation in coil made magnetostriction materials produce deformation when electric current flow through the coil upper conductor, fiber grating obtains tuning (Arce-Diego J L, Lopez-Ruisanchez R, Lopez-Higuera J M. etc., magnetic field tunable fiber grating filtering rises, optics letter, 1997,22 (9): 603~605).
3, based on the mechanical stretching method (US Patent No 624681481) of piezoelectric effect: comprise a fiber grating, piezoelectric ceramics and the fixing base of piezoelectric ceramics.Fiber grating is bonded at the piezoelectric ceramics surface, piezoelectric ceramics is fixed on the base, and the voltage that applies on the piezoelectric ceramics makes its elongation or compression, realizes the tuning (people such as J.J.Pan of fiber grating, " utilize the fiber grating-stabilized WDM LASER Light Source of sealed package ", Chinese photon meeting in 1996).
Summary of the invention
The packaging system that the purpose of this invention is to provide a kind of fiber grating of scissors-type structure makes fiber grating can carry out temperature compensation and tunning effect simultaneously.
The technical solution used in the present invention is as follows:
Scheme 1: it comprises that two V-type bracket by hinges connect into the scissors-type structure, fiber grating is bonded between the long-armed inboard of two V-type supports, one end of one one metal wire is bonded in the medial surface of a V-type support galianconism, on another V-type support galianconism adjusting screw(rod) is housed, the other end wiry is bonded on the adjusting screw(rod), a V-type support is installed on the pedestal, it is bonding that medial surface is stained with the galianconism and the pedestal of a V-type support wiry, is stained with on the pedestal of fiber grating support lower end and has breach.
Scheme 2: its structure and scheme 1 are similar, just after an end of an one metal wire passes through bonding piezoelectric ceramics, piezoelectric ceramics are bonded in again the medial surface of a V-type support galianconism.
The present invention compares with background technology, and the beneficial effect that has is:
1) need not to apply prestress, to reach required wavelength to fiber grating;
2) can make the unsettled setting of fiber grating itself, can guarantee fiber grating uniform internal stress when fiber grating is stretched, can not produce chirped grating;
3) can also combine with piezoelectric ceramics,, can expand the tuning range of fiber grating bragg wavelength so jointly to the fiber grating stress application;
4) adjusting of dependent variable is only relevant with tinsel, and irrelevant with the material of V-type support, so simplified design greatly;
This packaging system can be widely used on the various fiber bragg grating devices, as road device, multiplexing and demodulation multiplexer, tuned filter and fiber grating external cavity laser about the optical wavelength, in the optical fiber grating sensing field numerous application is arranged also simultaneously.
Description of drawings
Fig. 1 is the structural representation of the packaging system of fiber grating of the present invention;
Fig. 2 is the another kind of structural representation of the packaging system of fiber grating of the present invention;
Fig. 3 is the base construction synoptic diagram of packaging system of the fiber grating of invention;
Embodiment
In conjunction with the accompanying drawings embodiments of the invention are described in detail below:
As Fig. 1, shown in Figure 3, it comprises 1, one pedestal 4 of 2, one screw rods of a fiber grating 6, one one metal wires and two V-type supports 5 and 7.Two V-type supports 5,7 couple together by middle hinge 8 and form the scissors-type structure, then with fiber grating 6 by epoxy resin bonding between the medial surface of the left side of two V-type supports 5,7.Then with tinsel 2 one ends also by epoxy resin bonding in lower end, support 5 right side, on another V-type support 7 galianconism adjusting screw(rod) 1 is housed, the other end wiry by epoxy resin bonding on screw rod 1.By retainingf key or epoxy resin bonding, the lower-left end freely stretches with the bottom righthand side of V-type support 5 and pedestal 4, is stained with on the pedestal 4 of fiber grating 6 support lower ends and has breach 10.Elder generation's adjusting screw(rod) 1, make fiber grating 6 reach required wavelength X B, after temperature raises, the refractive index of fiber cores and the cycle of fiber grating all will become greatly, thereby the tuning wavelength of fiber grating will move to the long wave direction, and tinsel 2 is because thermal expansivity is bigger than optical fiber, its swell increment is also big than optical fiber, relies on two V- type supports 5,7 that couple together by middle hinge 8, fiber grating 6 suffered stress are diminished, thereby compensated the wave length shift of fiber grating.
Another kind of structure of the present invention as shown in Figure 2, device comprises 4, one piezoelectric ceramics 9 of 1, one pedestal of 2, one screw rods of a fiber grating 6, one one metal wires and two V-type supports 5 and 7.Its principle and scheme 1 are similar, just added piezoelectric ceramics 9, tinsel 2 one ends by epoxy resin bonding in lower end, V-type support 5 right side, tinsel 2 other ends and screw rod 1 are by the epoxy resin adhesion, so the tuning range of its fiber grating bragg wavelength has just become the summation of screw rod 1 and piezoelectric ceramics 9 tuning ranges, thereby reach the effect of the tuning range that increases wavelength.