Adjustable lay the grain power divider
Technical field
The present invention relates to a kind of adjustable lay the grain power divider, belong to the optical communication technique field.
Background technology
Luminous-power distributor based on fiber coupler has obtained tremendous development in recent years.Mainly be because optical fiber cable TV (CATV) reaches the progressively popularization and application that Fiber to the home (FTTH).Its market demand is increasing, and according to the prediction of RHK company, the market scale of fiber coupler will be to surpass 100% speed increase every year after 2003.See the great potential in luminous-power distributor market, many manufacturers that were engaged in plane waveguiding device have originally also actively developed the research and development and the market development work of similar device.Its performance and operation principle and optical-fiber type device are similar substantially.General optical-fiber type or waveguide devices all can only provide fixing splitting ratio.Development along with telecommunication service, but telco provider can control part scheduling resource at a plurality of even each website, the luminous power more than needed of each bar branch road can be greatly reduced, thereby save quite a few image intensifer, reduce the cost and the operating cost of whole system, thereby improve reliability of service and flexibility, increase income.Therefore, adopt adjustable luminous-power distributor.The way that general adjustable lay the grain power divider adopts the pyrometric cone at general optical-fiber type coupler partly to add stress changes the method for the splitting ratio of two outlets.The shortcoming of this method is that adjustable range is little, polarization degree of correlation height, and control precision is low.Therefore, its using value is very limited.
Summary of the invention
The objective of the invention is to adopt the adjustment luminous-power distributor that divides actinic light and polarized light interference technique to make based on birefringece crystal, a kind of design of brand-new optic communication device is provided, can increase the flexibility at light networking, can overcome above-mentioned shortcoming.The present invention program is based on crystal micro-optic technology, makes easily and realizes.
Technical scheme of the present invention has two kinds, a kind of is that input is exactly a polarised light, change input polarization by liquid crystal (LC) unit or other element that can change polarization state, carry out polarization spectro by crystal polarization beam apparatus or wollaston prism then and be coupled to output, the input of this scheme adopts micro-optic single-core fiber collimater, and output adopts micro-optic twin-core fiber collimater; Another kind is to be input as non-polarized light, by crystal polarization beam apparatus (walk-off crystal) and wave plate it is become polarised light, change input polarization by liquid crystal (LC) unit or other element that can change polarization state then, carry out polarization spectro by crystal polarization beam apparatus or wollaston prism (wallaston prism) again, be coupled to output, the input of this scheme of this scheme adopts micro-optic single-core fiber collimater, and output adopts micro-optic twin-core fiber collimater.
Adjustable lay the grain power division implement body comprises an input port, two outputs and optical power distribution devices thereof, input, output adopt collimater, the polarised light of input is adjusted the input polarization state of light by the element that can change polarization state, carry out polarization beam apparatus then, be coupled to output at last.
Described adjustable lay the grain power divider, the element that can change polarization state is liquid crystal cells or wave plate.
Described adjustable lay the grain power divider, polarization beam apparatus is crystal polarization beam apparatus or wollaston prism.
Described adjustable lay the grain power divider, it is made up of collimater, liquid crystal cells, crystal polarization beam apparatus, roof prism, twin-core collimater successively, and liquid crystal cells changes the polarization of incident light attitude under the driving of voltage.
Described adjustable lay the grain power divider, it is made up of collimater, liquid crystal cells, wollaston prism, twin-core collimater successively, liquid crystal cells changes the polarization of incident light attitude under the driving of voltage, by wollaston prism light is divided into the two bundle polarised lights that have angle again, this two-beam is coupled into the two-way of twin-core collimater.
Described adjustable lay the grain power divider, it is successively by single core collimater 1, crystal polarization beam apparatus 3-4, half-wave plate 6, liquid crystal cells 2, crystal polarization beam apparatus 3-2, half-wave plate 6-1, crystal polarization beam apparatus 3-3, roof prism 4, twin-core collimater 5 is formed, light is divided into two horizontal bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 3-4, make wherein a branch of it be become and another bundle polarization state of light identical linearly polarized light again by first half-wave plate 6, this two bunch polarised light is changed polarization state through behind the liquid crystal cells 2, again through the second crystal polarization beam apparatus 3-2, each bundle light is divided into two bundle polarised lights longitudinally again, this four bundles light is combined into parallel two-beam up and down through behind the second half-wave plate 6-1 and the 3rd crystal polarization beam apparatus 3-3, through being coupled into the two-way output of twin-core collimater 5 behind the deviation of roof prism 4 respectively.
Described adjustable lay the grain power divider, it is made up of single core collimater 1, crystal polarization beam apparatus 4-1, half-wave plate 4-3, liquid crystal cells 2, wollaston prism 4-5, half-wave plate 4-4, crystal polarization beam apparatus 4-2, twin-core collimater 5 successively, light is divided into horizontal two bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 4-1, makes wherein a branch of it be become and the identical linearly polarized light of another bundle polarization state of light by the first half-wave plate 4-3 again; This two bunch polarised light is changed polarization state through behind the liquid crystal cells 2, pass through wollaston prism 4-5 again, each bundle light is divided into two vertically angled bundle polarised lights again, this four bundles light is combined into two-beam up and down after through the second half-wave plate 4-4 and the second crystal polarization beam apparatus 4-2, is coupled into the two-way output of twin-core collimater 5 respectively.
Described adjustable lay the grain power divider, it is successively by single core collimater 1, crystal polarization beam apparatus 5-1, half-wave plate 5-3, liquid crystal cells, crystal polarization beam apparatus 5-2, total reflective mirror 5-4, total reflective mirror 5-5, half-wave plate 5-6, crystal polarization beam apparatus 5-7, roof prism 4, twin-core collimater 5 is formed, light is divided into two horizontal bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 5-1, make wherein a branch of it be become and another bundle polarization state of light identical linearly polarized light again by the first half-wave plate 5-3, this two bunch polarised light is changed polarization state through behind the liquid crystal cells 2, again through the second crystal polarization beam apparatus 5-2, each bundle light is divided into two bundle polarised lights longitudinally again, this four bundles light is through two mutual total reflective mirror 5-4 at an angle of 90, after the 5-5 reflection, be combined into parallel two-beam up and down after entering the second half-wave plate 5-6 and the 3rd crystal polarization beam apparatus 5-7, through being coupled into the two-way output of twin-core collimater 5 behind the deviation of roof prism 4 respectively.
Described adjustable lay the grain power divider, it is by single core collimater 1, crystal polarization beam apparatus 6-1, half-wave plate 6-2, total reflective mirror 6-3,0-1/2 wave plate 7, total reflective mirror 6-4, crystal polarization beam apparatus 6-5, half-wave plate 6-6, crystal polarization beam apparatus 6-7, roof prism 4, twin-core collimater 5 are formed successively; Light is divided into two horizontal bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 6-1, make wherein a branch of it be become and another bundle polarization state of light identical linearly polarized light again by the first half-wave plate 6-2, this two bunch polarised light is changed polarization state through the first mirror reflects 6-3 behind 0-1/2 wave plate 7, the second crystal polarization beam apparatus 6-5 is passed through in reflection through the second speculum 6-4 again, each bundle light is divided into two bundle polarised lights longitudinally again, after entering the second half-wave plate 6-6 and the 3rd crystal polarization beam apparatus 6-7, this four bundles light is combined into parallel two-beam up and down, through being coupled into the two-way output of twin-core collimater 5 behind the deviation of roof prism 4 respectively; 0-1/2 wave plate 7 is to be full-wave plate on one side, and thickness increases to half-wave plate gradually then, and the position of coming control beam to be incident on the 0-1/2 wave plate 7 by stepping motor 8 changes the phase delay of incident beam, thereby changes splitting ratio.
Described adjustable lay the grain power divider, it is successively by single core collimater 1, crystal polarization beam apparatus 8-1, half-wave plate 8-2, liquid crystal cells 2-1, crystal polarization beam apparatus 8-3, total reflective mirror 8-4, polarization beam splitting PBS cube 9, liquid crystal cells 2-2 and liquid crystal cells 2-3, crystal polarization beam apparatus 8-6 and crystal polarization beam apparatus 8-9, half-wave plate 8-7 and half-wave plate 8-10, crystal polarization beam apparatus 8-8 and crystal polarization beam apparatus 8-11, roof prism 4-A and 4-B, twin-core collimater 5-A and 5-B form, light is divided into two horizontal bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 8-1, wherein a branch of becomes it and another bundle polarization state of light identical linearly polarized light by the first half-wave plate 8-2, be changed polarization state behind this two bunch polarised light process liquid crystal cells 2-1, again through the second crystal polarization beam apparatus 8-3, each bundle light is divided into two bundle polarised lights longitudinally again, after reflecting through the first total reflective mirror 8-4, this four bundles light enters polarization beam splitting PBS cube 9, wherein two bundle reflections of polarization beam splitting PBS cube 9, other two bundle transmissions; Be changed polarization state behind the two-beam process liquid crystal cells 2-2 of reflection, again through the 3rd crystal polarization beam apparatus 8-6, each bundle light is divided into two bundle polarised lights longitudinally again, after entering the second half-wave plate 8-7 and the 4th crystal polarization beam apparatus 8-8, this four bundles light is combined into parallel two-beam up and down, through being coupled into the two-way output of the first twin-core collimater 5-A behind the deviation of the first roof prism 4-A respectively; After the two-beam of transmission is reflected 8-5 by second total reflective mirror, change polarization state through liquid crystal cells 2-3, again through the 5th crystal polarization beam apparatus 8-9, each bundle light is divided into two bundle polarised lights longitudinally again, after entering the 3rd half-wave plate 8-10 and the 6th crystal polarization beam apparatus 8-11, this four bundles light is combined into parallel two-beam up and down, through being coupled into the two-way of the second twin-core collimater 5-B behind the deviation of the second roof prism 4-B respectively.
Advantage of the present invention: the element that utilization of the present invention can change polarization state changes input polarization, thereby changes two-way flexibly, the four tunnel even the splitting ratio of multichannel light path more, makes engineer more design flexible and configuration optical-fiber network.
Description of drawings
Fig. 1: the adjustable lay the grain power divider of polarization relationship type that adopts crystal polarization beam apparatus and LC adjustment unit;
Fig. 2: the adjustable lay the grain power divider of polarization relationship type that adopts Wollaston (wallaston) prism and LC adjustment unit;
Fig. 3: the adjustable lay the grain power divider of polarization independent type that adopts crystal polarization beam apparatus and LC adjustment unit;
Fig. 4: the adjustable lay the grain power divider of polarization independent type of adopting wollaston prism and LC adjustment unit;
Fig. 5: a kind of reflective structure that is Fig. 3 embodiment;
Fig. 6: adopt motor to drive a kind of embodiment of 0-1/2 wave plate as adjustment unit;
Fig. 7: 0-1/2 wave plate schematic diagram;
Fig. 8: a kind of one the tunnel is divided into four tunnel adjustable lay the grain power divider embodiment.
Embodiment
The present invention has two class application modes, and a kind of is to distribute at the linearly polarized light luminous power, and another kind is to distribute at random polarization state light luminous power.
Fig. 1 is a kind of embodiment of linearly polarized light luminous-power distributor, and it is made up of collimater 1, liquid crystal cells (LC) 2, crystal polarization beam apparatus 3, roof prism 4, twin-core collimater 5.Linearly polarized light A is from the collimater outgoing, through liquid crystal (LC) unit 2, liquid crystal (LC) unit 2 changes the polarization of incident light attitude under the driving of voltage, by crystal polarization beam apparatus 3 (walk-off crystal) light is divided into parallel two bundle polarised light light S, P again, this two bundles polarised light light meets at some two-way that is coupled into twin-core collimater 5 output B1, B2 under the refraction of roof prism 4.The mechanism that liquid crystal cells changes polarization state has two kinds: whirling vibration face and change phase delay.
The liquid crystal cells of whirling vibration face makes the vibration of the incident light θ that rotates a certain angle, when its during by the walk-off crystal, the light intensity of separated two-way light is:
I
1=I
0*cos
2θ
I
2=I
0* sin
2θ=I
0* (1-cos
2θ) I
0Light intensity for incident light.
During change in voltage on being added in liquid crystal, anglec of rotation θ changes, and then the light intensity of the two-way light in the twin-core collimater also changes thereupon, thereby has realized the change of splitting ratio.
Fast axle becomes the liquid crystal cells of the changed phase delay of 45 degree to make the linearly polarized light of incident become the elliptically polarized light that a phase delay is φ (cos φ, isin φ) with the incident light vibration plane, when it passed through the walk-off crystal, the light intensity of separated two-way light was:
I
1=I
0*cos
2φ
I
2=I
0*sin
2φ=I
0*(1-cos
2φ)
During change in voltage on being added in liquid crystal, phase delay φ changes, and then the light intensity of the two-way light in the twin-core collimater also changes thereupon, thereby has realized the change of splitting ratio.
Fig. 2 is a kind of embodiment of linearly polarized light luminous-power distributor, and it is made up of collimater 1, liquid crystal cells (LC) 2, wollaston prism (wallaston prism) 3-1, twin-core collimater 5.Light is from collimater 1 outgoing, through liquid crystal (LC) unit 2, liquid crystal (LC) unit 2 changes the polarization of incident light attitude under the driving of voltage, by the wallaston prism light is divided into two bundle polarised light light S, the P that has angle again, and two-way B1, the B2 of twin-core collimater advanced in this two bundles polarised light optical coupling.
Fig. 3 is a kind of embodiment to random polarization state light luminous-power distributor, it is successively by single core collimater 1, crystal polarization beam apparatus 3-4, half-wave plate 6, liquid crystal cells 2, crystal polarization beam apparatus 3-2, half-wave plate 6-1, crystal polarization beam apparatus 3-3, roof prism 4, twin-core collimater 5 is formed, light A is divided into two horizontal bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 3-4, make wherein a branch of it be become and another bundle polarization state of light identical linearly polarized light again by first half-wave plate, this two bunch polarised light is changed polarization state through behind the liquid crystal cells 2, again through the second crystal polarization beam apparatus 3-2, each bundle light is divided into two bundle polarised lights longitudinally again, this four bundles light is combined into parallel two-beam up and down through behind the second half-wave plate 6-1 and the 3rd crystal polarization beam apparatus 3-3, through being coupled into the two-way output B1 of twin-core collimater 5 behind the deviation of roof prism 4 respectively, B2.
Fig. 4 is the adjustable lay the grain power divider of polarization independent type that adopts wollaston prism and LC adjustment unit: it is made up of single core collimater 1, crystal polarization beam apparatus 4-1, half-wave plate 4-3, liquid crystal cells 2, wollaston prism 4-5, half-wave plate 4-4, crystal polarization beam apparatus 4-2, twin-core collimater 5 successively, light is divided into horizontal two bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 4-1, makes wherein a branch of it be become and the identical linearly polarized light of another bundle polarization state of light by the first half-wave plate 4-3 again; This two bunch polarised light is changed polarization state through behind the liquid crystal cells 2, pass through wollaston prism 4-5 again, each bundle light is divided into two vertically angled bundle polarised lights again, this four bundles light is combined into two-beam up and down after through the second half-wave plate 4-4 and the second crystal polarization beam apparatus 4-2, is coupled into two-way output B1, the B2 of twin-core collimater 5 respectively.
Fig. 5 is a kind of reflective structure of Fig. 3 embodiment: it is successively by single core collimater 1, crystal polarization beam apparatus 5-1, half-wave plate 5-3, liquid crystal cells, crystal polarization beam apparatus 5-2, total reflective mirror 5-4, total reflective mirror 5-5, half-wave plate 5-6, crystal polarization beam apparatus 5-7, roof prism 4, twin-core collimater 5 is formed, light is divided into two horizontal bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 5-1, make wherein a branch of it be become and another bundle polarization state of light identical linearly polarized light again by the first half-wave plate 5-3, this two bunch polarised light is changed polarization state through behind the liquid crystal cells 2, again through the second crystal polarization beam apparatus 5-2, each bundle light is divided into two bundle polarised lights longitudinally again, this four bundles light is through two mutual total reflective mirror 5-4 at an angle of 90, after the 5-5 reflection, be combined into parallel two-beam up and down after entering the second half-wave plate 5-6 and the 3rd crystal polarization beam apparatus 5-7, through being coupled into the two-way output B1 of twin-core collimater 5 behind the deviation of roof prism 4 respectively, B2.
Fig. 6 adopts motor to drive a kind of embodiment of 0-1/2 wave plate as adjustment unit: it is by single core collimater 1, crystal polarization beam apparatus 6-1, half-wave plate 6-2, total reflective mirror 6-3,0-1/2 wave plate 7, total reflective mirror 6-4, crystal polarization beam apparatus 6-5, half-wave plate 6-6, crystal polarization beam apparatus 6-7, roof prism 4, twin-core collimater 5 are formed successively; Light is divided into two horizontal bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 6-1, make wherein a branch of it be become and another bundle polarization state of light identical linearly polarized light again by the first half-wave plate 6-2, this two bunch polarised light is changed polarization state through the first mirror reflects 6-3 behind 0-1/2 wave plate 7, the second crystal polarization beam apparatus 6-5 is passed through in reflection through the second speculum 6-4 again, each bundle light is divided into two bundle polarised lights longitudinally again, this four bundles light is combined into parallel two bundle polarised lights up and down after entering the second half-wave plate 6-6 and the 3rd crystal polarization beam apparatus 6-7, through being coupled into the two-way output of twin-core collimater 5 behind the deviation of roof prism 4 respectively; 0-1/2 wave plate 7 is to be full-wave plate on one side, and thickness increases to half-wave plate gradually then, and the position of coming control beam to be incident on the 0-1/2 wave plate 7 by stepping motor 8 changes the phase delay of incident beam, thereby changes splitting ratio.
Fig. 8 a kind of one the tunnel is divided into four tunnel the described adjustable lay the grain power divider of adjustable lay the grain power divider embodiment: it is successively by single core collimater 1, crystal polarization beam apparatus 8-1, half-wave plate 8-2, liquid crystal cells 2-1, crystal polarization beam apparatus 8-3, total reflective mirror 8-4, polarization beam splitting PBS cube 9, liquid crystal cells 2-2 and liquid crystal cells 2-3, crystal polarization beam apparatus 8-6 and crystal polarization beam apparatus 8-9, half-wave plate 8-7 and half-wave plate 8-10, crystal polarization beam apparatus 8-8 and crystal polarization beam apparatus 8-11, roof prism 4-A and 4-B, twin-core collimater 5-A and 5-B form, light is divided into two horizontal bundle polarised lights from single core collimater 1 outgoing through the first crystal polarization beam apparatus 8-1, wherein a branch of becomes it and another bundle polarization state of light identical linearly polarized light by the first half-wave plate 8-2, be changed polarization state behind this two bunch polarised light process liquid crystal cells 2-1, again through the second crystal polarization beam apparatus 8-3, each bundle light is divided into two bundle polarised lights longitudinally again, after reflecting through the first total reflective mirror 8-4, this four bundles light enters polarization beam splitting PBS cube 9, wherein two bundle polarised light reflections of polarization beam splitting PBS cube 9, other two bundle polarized light transmissions; Be changed polarization state behind the two bundle polarised lights process liquid crystal cells 2-2 of reflection, again through the 3rd crystal polarization beam apparatus 8-6, each bundle light is divided into two bundle polarised lights longitudinally again, this four bundles light is combined into parallel two bundle polarised lights up and down after entering the second half-wave plate 8-7 and the 4th crystal polarization beam apparatus 8-8, through being coupled into the two-way output of the first twin-core collimater 5-A behind the deviation of the first roof prism 4-A respectively; After two bundle polarised lights of transmission are reflected 8-5 by second total reflective mirror, change polarization state through liquid crystal cells 2-3, again through the 5th crystal polarization beam apparatus 8-9, each bundle light is divided into two bundle polarised lights longitudinally again, this four bundles light is combined into parallel two bundle polarised lights up and down after entering the 3rd half-wave plate 8-10 and the 6th crystal polarization beam apparatus 8-11, through being coupled into two-way output B1, the B2 of the second twin-core collimater 5-B behind the deviation of the second roof prism 4-B respectively.
Fig. 7: 0-1/2 wave plate schematic diagram: the 0-1/2 wave plate is to be λ for full-wave plate thickness on one side, and thickness increases to half-wave plate 3/2 λ gradually then.
In sum, core of the present invention is to utilize liquid crystal cells or wave plate to change the polarization of incident light attitude, the adjustable lay the grain power divider that is separated by polarization beam apparatus is its splitting ratio of controlling luminous-power distributor by the state that changes liquid crystal cells or wave plate again.Therefore, the invention is not restricted to above-mentioned execution mode.