CN104536091A - Non-damage tunable optical fiber power attenuator - Google Patents

Abstract

The invention discloses a non-damage tunable optical fiber power attenuator which comprises a threaded column and a base. The threaded column is fixed to the base, a pair of optical fiber clamps is arranged on the threaded column, the optical fiber clamps are provided with V-shaped grooves for accommodating optical fibers, and the optical fiber clamps and the threaded column are connected in a threaded mode and are opposite in rotating direction. The non-damage tunable optical fiber power attenuator utilizes bending loss of the optical fibers to achieve non-damage large-scale and high accuracy continuous power turning of an optical fiber system by adjusting the length of each optical fiber winded on the threaded column can be optionally inserted into the any position of an optical path, does not damage or change the original optical fiber system and is simple in structure, convenient to operate, reliable inter-member connection, good in stability, low in price and long in service life.

Description

A kind of not damaged tunable fiber power attenuator

Technical field

The present invention relates to a kind of optical electron device, particularly relate to a kind of not damaged tunable fiber power attenuator.

Background technology

Along with the fast development of optical fiber industry, people it is also proposed higher requirement to optic communication device.Optical attenuator is intended to a kind of device reducing transmitting optical power in waveguide.Need, with attenuator, signal intensity is reduced to required intensity in the path of Optical Fiber Transmission.For example for general spectrometer, the power of its input light can not exceed hundreds of milliwatt, otherwise will very easily cause the loss of device.Luminous power too high in photoreceiver will cause the distortion of electric signal and nonlinear increase, and then reduces the serviceable life of device.Therefore dependence test and process is carried out again after needing to decay to some light source.But the degree of decay is also not the smaller the better, in photoreceiver, if its luminous power is less than its best accept luminous power, then can cause the deterioration of the little and signal to noise ratio (S/N ratio) of signal amplitude.Therefore, provide a kind of realize damping capacity on a large scale, the optical power attenuation device of high precision, continuously adjustable is very necessary.

A kind of attenuator conventional is at present the attenuator that joint inserts, and this attenuator exists following problem: 1, a large amount of heats enters attenuator, easily burns out the connector of the joints of optical fibre or attenuator; 2, shank has part reflected light and returns along optical fiber, may cause the damage of light source or backing system; 3, have step evolution damping capacity, be difficult to realize from zero attenuation; 4, a lot of occasion optical fiber link is closed, cannot insert other optical device, need the plug that welding and plug-in type attenuator match, and this can increase fusing point, destroy the integrality of optical fiber link, and complicated operation.

Also have at present a kind of use more general method accesses one section of attenuating fiber in optical fibre channel, for consuming in Signal transmissions or attenuating part power input, and remainder can continue through this system.But this attenuating fiber needs to add impurity element during fabrication, and production cost is higher, and reliability and stability are poor.In addition, this method also can increase fusing point, complicated operation, destroy optical fiber link integrality and the pad value continuous print that is fixedly difficult to realize damping capacity is tuning.

Summary of the invention

Technical matters to be solved by this invention is to provide a kind of not damaged tunable fiber power attenuator, can realize damping capacity on a large scale, high-precision continuous tuning, and can arbitrarily insert optional position in light path, can not damage be caused to original fibre system or change, structure is simple, easy to operate, good stability.

The present invention solves the problems of the technologies described above the technical scheme adopted to be to provide a kind of not damaged tunable fiber power attenuator, comprise screw thread column and base, described screw thread column is fixed on base, described screw thread column is provided with a pair fiber clamp, described fiber clamp offers the V-shaped groove of receiving optical fiber, described a pair fiber clamp and screw thread column are connected by screw thread and sense of rotation is contrary.

Above-mentioned not damaged tunable fiber power attenuator, wherein, described fiber clamp comprises magnetic clamping plate, described V-shaped groove is located on described magnetic clamping plate, described magnetic clamping plate are provided with foldable compressing tablet, and described compressing tablet is provided with bullet pad, and described bullet pad is positioned at the top of V-shaped groove.

Above-mentioned not damaged tunable fiber power attenuator, wherein, described a pair fiber clamp is oppositely arranged up and down, and on described a pair fiber clamp, the turnover direction of compressing tablet is contrary.

Above-mentioned not damaged tunable fiber power attenuator, wherein, the diameter range of described screw thread column is 4mm ~ 10mm.

Above-mentioned not damaged tunable fiber power attenuator, wherein, for single-mode fiber, the diameter of described screw thread column, according to the bending loss of optical fiber of required adjustment, is determined by following relation:

$A=\frac{\mathrm{\π}}{2R}\frac{{10}^4}{\sqrt{\mathrm{\Δ}}}{10}^{1.29-2.17\mathrm{\ξ}{R}_n-0.58{\mathrm{\ξ}}^2{R_n}^2}(\mathrm{dB}/\mathrm{cm})$

Wherein, ξ=Δ ^3/21.137 ^Δ-0.01, R _n=n ₂r/ λ ₀, Δ=(n ₁-n ₂)/n ₂; R is the bending radius of optical fiber, and fibre-optical bending diameter 2R is the diameter of screw thread column, λ ₀for operation wavelength, n ₁and n ₂be respectively the refractive index of fiber core and covering, Δ is the relative index of refraction of optical fiber, λ ₀with the unit of R be μm.

The present invention contrasts prior art following beneficial effect: not damaged tunable fiber power attenuator provided by the invention, utilize the bending loss of optical fiber, by regulate the length that is wrapped in optical fiber on screw thread column thus realize the not damaged of fibre system, on a large scale, high-precision continuous power is tuning, and can arbitrarily insert optional position in light path, can not damage be caused to original fibre system or change, structure is simple, easy to operate, connect reliable between component, good stability, cheap, long service life.

Accompanying drawing explanation

Fig. 1 is not damaged tunable fiber power attenuator structural representation of the present invention.

Fig. 2 is the structural representation of fiber clamp in optical fiber power attenuator in the present invention;

Fig. 3 is that optical fiber power attenuator of the present invention controls bending radius and bending loss schematic diagram;

Fig. 4 is the structural representation of an optical fiber power attenuator of the present invention embody rule example.

In figure:

1 fiber clamp 2 screw thread column 3 base

11 high-power semiconductor laser 12 bundling device 13 gain fibres

14 high reflectance fiber grating 15 antiradar reflectivity fiber grating 16 optical fiber power attenuators

17 energy-transmission optic fibre 18 spectrometer 101 magnetic clamping plate

102 compressing tablet 103 bullet pad 104 V-shaped grooves

Embodiment

Below in conjunction with drawings and Examples, the invention will be further described.

Fig. 1 is not damaged tunable fiber power attenuator structural representation of the present invention; Fig. 2 is the structural representation of fiber clamp in optical fiber power attenuator in the present invention.

Refer to Fig. 1 and Fig. 2, not damaged tunable fiber power attenuator provided by the invention comprises screw thread column 2 and base 3, described screw thread column 2 is fixing on the base 3, described screw thread column 2 is provided with a pair fiber clamp 1, described fiber clamp 1 offers the V-shaped groove 104 of receiving optical fiber, described a pair fiber clamp 1 and screw thread column 2 are connected by screw thread and sense of rotation is contrary.

Not damaged tunable fiber power attenuator provided by the invention, wherein, described fiber clamp 1 comprises magnetic clamping plate 101, described V-shaped groove 104 is located on described magnetic clamping plate 101, described magnetic clamping plate 101 are provided with foldable compressing tablet 102, described compressing tablet 102 is provided with bullet pad 103, and described bullet pad 103 is positioned at the top of V-shaped groove 104, and optical fiber can slightly slide in fixture.Described screw thread column 2 is covered with the screw thread of equivalent diameter; Described magnetic clamping plate 101 have screw thread, and the screw thread of diameter and screw thread column matches, can spiral rotating on screw thread column 2.Described a pair fiber clamp 1 is preferably oppositely arranged up and down and is positioned on screw thread column, and on described a pair fiber clamp 1, the turnover direction of compressing tablet 102 is contrary, and target is carried out, and the optical fiber of power attenuation can be level and smooth is wrapped on screw thread column 2.

Fig. 3 is that optical fiber power attenuator of the present invention controls bending radius and bending loss schematic diagram.

Please continue see Fig. 3, principle of the present invention is, except the splice loss, splice attenuation of optical fiber and the junction loss of optical fiber, the loss of optical fiber also derives from the bending of optical fiber.This is because when fibre-optical bending, the mould conducted in optical fiber can due to radiation loss luminous power.The size of bending loss and the inversely proportional relation of winding radius of optical fiber.When fibre-optical bending, the loss of unit length optical fiber is wound around radius by it and determines, when radius-of-curvature is greater than a critical value Rc, bending loss is very little negligible; But when radius-of-curvature is less than critical value Rc, exponentially rule increases sharply by additional loss.The present invention based on optical fiber macrobending loss rule and design: unit length fibre loss one timing, by change winding optical fiber length thus make the loss of optical fiber adjustable.

For single-mode fiber, for the optical fiber of unit length, the relation between its bending loss and its bending radius can be reduced to following formula:

$A=\frac{\mathrm{\π}}{2R}\frac{{10}^4}{\sqrt{\mathrm{\Δ}}}{10}^{1.29-2.17\mathrm{\ξ}{R}_n-0.58{\mathrm{\ξ}}^2{R_n}^2}(\mathrm{dB}/\mathrm{cm})$

Wherein ξ=Δ ^3/21.137 ^Δ-0.01, R _n=n ₂r/ λ ₀, Δ=(n ₁-n ₂)/n ₂; R is the bending radius of optical fiber, λ ₀for operation wavelength, n ₁and n ₂be respectively the refractive index of fiber core and covering, Δ is the relative index of refraction of optical fiber.λ ₀with the unit of R be μm.With Matlab, analog simulation is carried out to above formula, the variation diagram of bending loss and bending radius can be drawn, as seen from Figure 3, bending radius more subsection length of fibre introduce loss larger, when bending radius is at below 5mm, bending loss will increase fast.Therefore, column diameter general control of the present invention is between 4mm ~ 10mm, and such optical fiber both can introduce considerable waste, can not cause damage again to optical fiber.In actual applications, the attenuator in the present invention can be operated one section of optical fiber any in light path, first by optical fiber clamping in two fixtures, optical fiber slightly can slide in fixture, gently rolling clamp, makes optical fiber along screw thread uniform winding on column.By changing the position that two fiber clamps rotate on screw thread column and then the coiling length changing optical fiber, thus achieve the continuous decay of optical fiber power.Because the length controlled range of winding optical fiber is large, can realize zero starting point damping capacity, on a large scale, the decay of continuously adjustable.Can realize high-precision attenuation tunable by minor rotation fiber clamp, such as can arrange a lock-screw at the threaded hole place of magnetic clamping plate, after chucking position is determined, tightening screw is to hold out against stud thus to realize the fixing of fixture.This apparatus structure is simple, easy to operate, connects reliable, good stability between component, cheap, long service life, and can not cause damage to original fibre system or change.

Fig. 4 is the structural representation of an optical fiber power attenuator of the present invention embody rule example.

Please continue see Fig. 4, the object of this example is the laser spectrum of a measurement high-power fiber grating laser.The formation of this high-power fiber grating laser is that high-power semiconductor laser 11 is coupled into gain fibre 13 through bundling device 12, and the two ends of laser cavity are high reflectance fiber grating 14 and antiradar reflectivity fiber grating 15.In order to prevent the output of high power laser light, damage is caused to spectrometer 18, the energy-transmission optic fibre 17 that after antiradar reflectivity fiber grating 15 one section outer cladding diameter is 125 μm is wound on optical fiber power attenuator 16 provided by the invention by the present invention, by regulating the relative position on screw thread of two fixtures in optical fiber power attenuator 16, thus change coiling length and the bending loss size of energy-transmission optic fibre 17, and then re-shoot to spectrometer 18 after laser power is decayed to suitable size.For preventing the spurious oscillation in laser instrument, the other end incisal bevel of energy-transmission optic fibre 17.The laser that this inclined-plane exports is difficult to the attenuator using joint to insert, because have very large docking loss, the power attenuation that can not realize among a small circle is tuning.And the present invention can realize zero starting point damping capacity, on a large scale, the decay of continuously adjustable.Secondly the size of pumping source incident power can cause the change of optical fiber grating temperature, fiber grating reflection peak is caused to drift about with temperature, the operation wavelength of laser instrument also can change, therefore by the change of optical maser wavelength can be caused while adjustment pumping source size tuning laser power, the accuracy of wavelength measurement is affected.But by the invention provides optical fiber power attenuator 16, just can avoid, because the present invention only can decay to optical fiber power and can not change the wavelength of laser.

Although the present invention discloses as above with preferred embodiment; so itself and be not used to limit the present invention, any those skilled in the art, without departing from the spirit and scope of the present invention; when doing a little amendment and perfect, therefore protection scope of the present invention is when being as the criterion of defining with claims.

Claims (5)

1. a not damaged tunable fiber power attenuator, it is characterized in that, comprise screw thread column (2) and base (3), described screw thread column (2) is fixed on base (3), described screw thread column (2) is provided with a pair fiber clamp (1), described fiber clamp (1) offers the V-shaped groove (104) of receiving optical fiber, described a pair fiber clamp (1) and screw thread column (2) are connected by screw thread and sense of rotation is contrary.

2. not damaged tunable fiber power attenuator as claimed in claim 1, it is characterized in that, described fiber clamp (1) comprises magnetic clamping plate (101), described V-shaped groove (104) is located on described magnetic clamping plate (101), described magnetic clamping plate (101) are provided with foldable compressing tablet (102), described compressing tablet (102) is provided with bullet pad (103), and described bullet pad (103) is positioned at the top of V-shaped groove (104).

3. not damaged tunable fiber power attenuator as claimed in claim 2, it is characterized in that, described a pair fiber clamp (1) is oppositely arranged up and down, and the turnover direction of the upper compressing tablet (102) of described a pair fiber clamp (1) is contrary.

4. the not damaged tunable fiber power attenuator as described in any one of claims 1 to 3, is characterized in that, the diameter range of described screw thread column (2) is 4mm ~ 10mm.

5. not damaged tunable fiber power attenuator as claimed in claim 4, it is characterized in that, for single-mode fiber, the diameter of described screw thread column (2), according to the bending loss of optical fiber of required adjustment, is determined by following relation:

$A=\frac{\mathrm{\π}}{2R}\frac{{10}^4}{\sqrt{\mathrm{\Δ}}}{10}^{1.29-2.17\mathrm{\ξ}{R}_n-0.58{\mathrm{\ξ}}^2{R_n}^2}(\mathrm{dB}/\mathrm{cm})$

Wherein, ξ=Δ ^3/21.137 ^Δ-0.01, R _n=n ₂r/ λ ₀, Δ=(n ₁-n ₂)/n ₂; R is the bending radius of optical fiber, and fibre-optical bending diameter 2R is the diameter of screw thread column, λ ₀for operation wavelength, n ₁and n ₂be respectively the refractive index of fiber core and covering, Δ is the relative index of refraction of optical fiber, λ ₀with the unit of R be μm.