The polarized light interference method that is used for Comb for dividing waves
Technical field
The present invention relates to a kind of polarized light interference method that is used for Comb for dividing waves, belong to a kind of optical passive component that the optical communication technique field is used to separate the odd-even channel wavelength.
Background technology
Along with the development of present telecommunication service, people are increasing to the demand of data bandwidth, so development high capacity all-optical network solves the bandwidth demand that people increase day by day.Along with information transmitted amount in the optical fiber grows with each passing day, to the demands for higher performance of optical passive components such as dense wave division multipurpose (DWDM), photoswitch.Present dense wave division multipurpose (DWDM) mainly adopts methods such as grating, optical waveguide, interference filter, birefringence filtering.Along with the dense wave division multipurpose channel density further improves, we need a kind of better method separate signal and close the road signal.Adopting the wavelength division device of birefringece crystal filter plate is exactly a kind of method preferably, but the refringence of ordinary light in the birefringece crystal and non-ordinary light is less, and this just makes size of devices be difficult to dwindle.
Summary of the invention
The objective of the invention is the optical path difference of utilizing light in various mediums, to propagate, two bundle polarized lights by different light-transmitting mediums, are formed the Comb for dividing waves device of birefringence optical filtering form, thus the reduction of device volume.
Technical scheme of the present invention is: the polarized light interference method of Comb for dividing waves is to adopt one group of polarization spectro element that a branch of light is divided into two vertical bunch polarized lights of vibration plane, make the orthogonal two-beam of vibration plane produce optical path difference by different light-transmitting mediums two-beam then, again two-beam is closed bundle.
The described polarized light interference method that is used for Comb for dividing waves, its input light 111 is divided into two the orthogonal light beam 112a of vibration plane, 112b through polarization splitting prism 212, light beam 112a, 112b are by behind different light-transmitting medium 214a, the 214b, be combined into a branch of light 114 through polarization light-combining prism 215, polarization splitting prism 212 is placed with polarization light-combining prism 215 symmetries, reflect a kind of polarization state simultaneously, and the another kind of vertical polarization attitude of transmission.
The described polarized light interference method that is used for Comb for dividing waves, it is that p ripple and 122b are the s ripple that its incident ray 121 process polarization splitting prisms, 212 reflections and transmission are divided into the orthogonal smooth 122a of two bundle vibration planes, light 122a, 122b is through behind λ/2 phase delay chips 213, light 122a becomes s ripple 123a, light 122b becomes p ripple 123b, light 123a, 123b passes through light-transmitting medium 214a respectively, behind the 214b, light 123b is combined into Ray Of Light 124 through 215 reflections of polarization light-combining prism with 123a, and polarization splitting prism 212 is placed with polarization light-combining prism 215 a Rotate 180s ° symmetry.
The described polarized light interference method that is used for Comb for dividing waves, its incident ray 131 incides on the polarization splitting prism 212, it is that p ripple and 1 32b are the s ripple that 212 reflections of process polarization splitting prism and transmission are divided into the orthogonal smooth 132a of two bundle vibration planes, after light 132a, 132b pass through light-transmitting medium 214a, 214b respectively, be combined into Ray Of Light 134 through 215 reflections of polarization light-combining prism, polarization splitting prism 212 is placed with polarization light-combining prism 215 a Rotate 180s ° symmetry.
The described polarized light interference method that is used for Comb for dividing waves, it is that e ripple and 142b are the o ripple that its incident ray 141 process crystal polarizing beam splitters 212 refractions are divided into the orthogonal smooth 142a of two bundle vibration planes, after light 142a, 142b pass through light-transmitting medium 214a, 214b respectively, close luminescent crystal 225 refractions through the crystal polarization and be combined into Ray Of Light 144.
The described polarized light interference method that is used for Comb for dividing waves, its incident ray 151 incides on the crystal polarizing beam splitter 222, it is that e ripple and 152b are the o ripple that 222 refractions of process crystal polarizing beam splitter are divided into the orthogonal smooth 152a of two bundle vibration planes, light 152a, 152b are through behind λ/2 phase delay chips 213, light 152a becomes o ripple 153a, light 152b becomes e ripple 153b, after light 153a, 153b pass through light-transmitting medium 214a, 214b respectively, close luminescent crystal 225 refractions through the crystal polarization and be combined into Ray Of Light 154.
The described polarized light interference method that is used for Comb for dividing waves, its incident ray 161 incides on the polarization splitting prism 212, it is that p ripple and 162b are the s ripple that 212 reflections of process polarization splitting prism and transmission are divided into the orthogonal smooth 162a of two bundle vibration planes, light 162a, 162b is through behind λ/4 phase delay chips 233, light 162a, 162b passes through light-transmitting medium 214a respectively, behind the 214b, pass through light-transmitting medium 214a once more through reflector plate 234 reflections, 214b and λ/4 phase delay chips 233, twice by behind λ/4 phase delay chips 233, light 162a becomes s ripple 163a, light 162b becomes p ripple 163b, light 163a, 163b is combined into Ray Of Light 164 through polarization splitting prism 212 reflections.
The described polarized light interference method that is used for Comb for dividing waves, its incident ray 171 incides on the polarization splitting prism 212, it is that p ripple and 172b are the s ripple that 212 reflections of process polarization splitting prism and transmission are divided into the orthogonal smooth 172a of two bundle vibration planes, light 172a, 172b are through behind λ/4 phase delay chips 233, after light 172a, 172b pass through light-transmitting medium 214a, 214b respectively, pass through light-transmitting medium 214a, 214b and λ/4 phase delay chips 233 once more through right- angle prism 235a, 235b reflection.Twice light 172a becomes s ripple 173a by behind λ/4 phase delay chips 233, and light 172b becomes p ripple 173b, and light 173a, 173b are combined into Ray Of Light 174 through polarization splitting prism 212 reflections.
The described polarized light interference method that is used for Comb for dividing waves, any of different light-transmitting mediums that is used to transmit two-beam all can be combined by multiple medium.
Any two or more can being used in combination in the said method.
Advantage of the present invention has provided a kind of new method and has realized the phase delay of polarized light and produce interfering.First advantage of the present invention is to realize the polarization interference of light by the orthogonal polarized light of two vibration planes is produced phase delay by different optical transmission mediums, has dwindled device volume.Second advantage is to realize the polarization interference of light by reflection, further dwindled device volume.The 3rd advantage is can carry out desirable temperature compensation by light-transmitting medium or its combination of selecting the different temperatures characteristic for use, can improve the temperature stability of device greatly.The 4th advantage is by selecting for use functional material to can be made into other functional device, as devices such as photoswitch, optical attenuator, photomodulators.
Description of drawings
Below accompanying drawing is described: Fig. 1 is the structural representation and the index path of first kind of example of the present invention; Fig. 2 is the structural representation and the index path of second kind of example of the present invention; Fig. 3 is the structural representation and the index path of the third example of the present invention; Fig. 4 is the structural representation and the index path of the 4th kind of example of the present invention; Fig. 5 is the structural representation and the index path of the 5th kind of example of the present invention; Fig. 6 is the structural representation and the index path of the 6th kind of example of the present invention; Fig. 7 is the structural representation and the index path of the 7th kind of example of the present invention; Fig. 8 is the synoptic diagram that a kind of Comb for dividing waves device of the present invention is used; Fig. 9 is the synoptic diagram that the present invention is used for bipolar filtering Comb for dividing waves device; Figure 10 is the synoptic diagram of the present invention with two bipolar filtering Comb for dividing waves devices of reflection-type; Figure 11 is a kind of structural representation and index path of 200 assemblies commonly used; Figure 12 is a kind of structural representation and index path that uses 240 assemblies of reflecting prism; Figure 13 is a kind of structural representation and index path that uses 240 assemblies of polarization revolving fragment and plane mirror.Among the figure 111,121,131,141,151,161,171 represent incident light, 212 represent polarization splitting prism, 214 (a, b) represent different light-transmitting mediums respectively, 215 represent the polarization light-combining prism, on behalf of the crystal polarization, 225 close luminescent crystal, 112,122,123,132,142,152,153,162,163,172,173 (a, b) be respectively the orthogonal light of two bundle vibration planes, 234 is reflector plate, right- angle prism 235a, 235b, 213,201,202,205,206, the 208th, λ/2 phase delay chips, the 248th, reflection-type λ/4 phase delay chips, the 233rd, λ/4 phase delay chips, 114,124,134,144,154,164, the 174th, close bundle light, 250,251, the various Comb for dividing waves polarized light interference devices that 252 representatives make with method of the present invention, 181~184 (a, b), 191~195 (a, b), 300~305 (a, b) all represent light path, the 200th, polarization converter: mainly by crystal polarizing beam splitter 241, λ/2 phase delay chips 242, polarization mode dispersion compensator 243 and λ/2 phase delay chips 244 are formed, and the 240th, crystal divides reflective optical system: mainly by λ/2 phase delay chips 247, crystal polarizing beam splitter 245, right-angle prism 246 is formed.
Figure 14 is the phase delay figure that 100GHz is used for the polarized light interference device p light s light of Comb for dividing waves for the cycle, a1 i.e. solid line among the figure, represent the phase delay curve of the p light s light of the linear polarized light interference device that is used for Comb for dividing waves, a2 i.e. dotted line among the figure, represents flat type to be used for the phase delay curve of p light s light of the polarized light interference device of Comb for dividing waves.
Figure 15 shows that the 100GHz single-stage Comb for dividing waves device curve of spectrum, b1 i.e. solid line among the figure, the curve of spectrum of the Comb for dividing waves device that the polarized light interference device of representing linearity to be used for Comb for dividing waves is formed, b2 i.e. dotted line among the figure, represents flat type to be used for the curve of spectrum of Comb for dividing waves device of composition of the polarized light interference device of Comb for dividing waves.
Figure 16 shows that the 100GHz twin-stage Comb for dividing waves device curve of spectrum, c1 i.e. solid line among the figure, the curve of spectrum of the Comb for dividing waves device that the polarized light interference device of representing the single-stage flat type to be used for Comb for dividing waves is formed, c2 i.e. dotted line among the figure, represents the twin-stage flat type to be used for the curve of spectrum of Comb for dividing waves device of composition of the polarized light interference device of Comb for dividing waves.
Embodiment
Further specify the principle of work of various embodiment below in conjunction with accompanying drawing: can make the polarized light interference device of various Comb for dividing waves with method of the present invention, accompanying drawing 1~7 has provided the concrete structure figure of the polarized light interference device of 7 kinds of Comb for dividing waves.
Fig. 1 is that polarization splitting prism 212 is placed with polarization light-combining prism 215 symmetries, reflects a kind of polarization state simultaneously, and the embodiment of the another kind of vertical polarization attitude of transmission.Incident ray 111 incides on the polarization splitting prism 212 among the figure, is divided into two bundle orthogonal smooth 112a of vibration plane (p ripple) and 112b (s ripple) through polarization splitting prism 212 reflections and transmission.After light 112a, 112b passed through light-transmitting medium 214a, 214b respectively, light 112a was polarized light-combining prism 215 reflections and is combined into Ray Of Light 114 with light 112b.The orthogonal light wave p of two vibration planes ripple in the light 114, s ripple are owing to its light path difference of passing by, and its phase delay is also inequality.When not considering phase delay that polarization splitting prism itself brings, the phase delay of p ripple, s ripple is: δ=2 π/λ
*[(n
a-1)
*l
a-(n
b-1)
*l
b], λ is the incident light wavelength, n
aAnd l
aBe refractive index and the length of optical transmission medium 214a, n
bAnd l
bRefractive index and length for optical transmission medium 214b.Cycle be the phase delay of the 100GHz polarized light interference device that should be used for Comb for dividing waves and incident light frequency curve as shown in figure 14, the be separated by phase delay of light of 100GHz of light frequency is identical.
Fig. 2 is that polarization splitting prism 212 is placed with polarization light-combining prism 215 a Rotate 180s ° symmetry, and the centre adds the embodiment of λ/2 phase delay chips 213.Incident ray 121 incides on the polarization splitting prism 212 among the figure, is divided into two bundle orthogonal smooth 122a of vibration plane (p ripple) and 122b (s ripple) through polarization splitting prism 212 reflections and transmission.Light 122a, 122b are through behind λ/2 phase delay chips 213, and light 122a becomes s ripple 123a, and light 122b becomes p ripple 123b.After light 123a, 123b passed through light-transmitting medium 214a, 214b respectively, light 123b was combined into Ray Of Light 124 through 215 reflections of polarization light-combining prism with 123a.
Fig. 3 is polarization splitting prism 212 and the polarization light-combining prism 215 Rotate 180s ° embodiment that symmetry is placed.Incident ray 131 incides on the polarization splitting prism 212 among the figure, is divided into two bundle orthogonal smooth 132a of vibration plane (p ripple) and 132b (s ripple) through polarization splitting prism 212 reflections and transmission.After light 132a, 132b passed through light-transmitting medium 214a, 214b respectively, light 132a, 132b were combined into Ray Of Light 134 through 215 reflections of polarization light-combining prism.
Incident ray 141 incides on the crystal polarizing beam splitter 222 among Fig. 4, and 212 refractions are divided into two bundle orthogonal smooth 142a of vibration plane (e ripple) and 142b (o ripple) through the crystal polarizing beam splitter.After light 142a, 142b pass through light-transmitting medium 214a, 214b respectively, close luminescent crystal 225 refractions through the crystal polarization and be combined into Ray Of Light 144.
Incident ray 151 incides on the crystal polarizing beam splitter 222 among Fig. 5, and 222 refractions are divided into two bundle orthogonal smooth 152a of vibration plane (e ripple) and 152b (o ripple) through the crystal polarizing beam splitter.Light 152a, 152b are through behind λ/2 phase delay chips 213, and light 152a becomes o ripple 153a, and light 152b becomes e ripple 153b.After light 153a, 153b pass through light-transmitting medium 214a, 214b respectively, close luminescent crystal 225 refractions through the crystal polarization and be combined into Ray Of Light 154.
Incident ray 161 incides on the polarization splitting prism 212 among Fig. 6, is divided into two bundle orthogonal smooth 162a of vibration plane (p ripple) and 162b (s ripple) through polarization splitting prism 212 reflections and transmission.Light 162a, 162b after light 162a, 162b pass through light-transmitting medium 214a, 214b respectively, once more pass through light-transmitting medium 214a, 214b and λ/4 phase delay chips 233 through reflector plate 234 reflections through behind λ/4 phase delay chips 233.Twice light 162a becomes s ripple 163a by behind λ/4 phase delay chips 233, and light 162b becomes p ripple 163b.Light 163a, 163b are combined into Ray Of Light 164 through polarization splitting prism 212 reflections.
Incident ray 171 incides on the polarization splitting prism 212 among Fig. 7, is divided into two bundle orthogonal smooth 172a of vibration plane (p ripple) and 172b (s ripple) through polarization splitting prism 212 reflections and transmission.Light 172a, 172b after light 172a, 172b pass through light-transmitting medium 214a, 214b respectively, once more pass through light-transmitting medium 214a, 214b and λ/4 phase delay chips 233 through right- angle prism 235a, 235b reflection through behind λ/4 phase delay chips 233.Twice light 172a becomes s ripple 173a by behind λ/4 phase delay chips 233, and light 172b becomes p ripple 173b.Light 173a, 173b are combined into Ray Of Light 174 through polarization splitting prism 212 reflections.
Fig. 8 is a polarized light interference device example of using Comb for dividing waves of the present invention, and incident ray 180 becomes the identical two-beam of polarization state 181 by polarization converter 200 among the figure.Light 181 rotates to an angle through λ/2 phase delay chips, 201 rear polarizer attitudes, as 45 degree, and then becomes light 182 by the polarized light interference device 250 that is used for Comb for dividing waves.At this moment, the polarization state of light 182 is expressed as (0.707,0.707 with Jones vector
*Exp (i
*δ)), δ is the phase delay that is used for the polarized light interference device 250 of Comb for dividing waves.Light 182 is (cos (δ), i by the polarization state behind λ/2 phase delay chips 202
*Sin (δ)).By crystal polarizing beam splitter 203 time, be divided into two groups of 183a, 183b, 183a, 183b are combined into two light 184a, 184b through polarization converter 204.For wavelength is the light of λ, and the phase delay that is used for the polarized light interference device 250 of Comb for dividing waves is δ, and when δ=2 π, light is from the 184b outgoing; When δ=π, light is from the 184a outgoing.So just can constitute a simple Comb for dividing waves device, output spectrum such as Figure 15-b1.As optical transmission medium 214a, the 214b of the polarized light interference device 250 that is used for Comb for dividing waves when its light path is variable under certain condition, just may command incident light, make its part by, fully by or obstructed fully, this has just become photoswitch, optical attenuator or a photomodulator.
The application example that Fig. 9 is made up of four the present invention, incident ray 190 becomes the identical two-beam of polarization state 191 by polarization converter 200 among the figure.Light 191 rotates to an angle through λ/2 phase delay chips, 201 rear polarizer attitudes, as 45 degree, and then becomes light 192 by the polarized light interference device 250 that is used for Comb for dividing waves.Light 192 rotates to an angle through λ/2 phase delay chips, 205 rear polarizer attitudes, as-60 degree, and then becomes light 193 by the polarized light interference device 251 that is used for Comb for dividing waves.Light 193 is divided into two bundle 194a, 194b by behind λ/2 phase delay chips 206 by crystal optical splitter 203.194a, 194b be successively behind the polarized light interference device 252 by being used for Comb for dividing waves, λ/2 phase delay chips 208, the polarized light interference device 253 that is used for Comb for dividing waves, λ/2 phase delay chips 202, the polarization converter 204, closed Shu Chengwei light 195a, 195b by filtering again.When the cycle of the polarized light interference device 251 that is used for Comb for dividing waves is that the p ripple of light 193 when being used for the twice of polarized light interference device 250 of Comb for dividing waves, the phase delay of s ripple become nonlinear with wavelength change, it is smooth that the curve of spectrum of two-beam 194a, the 194b that get this moment will become, output spectrum such as Figure 15-b2.The polarized light interference device 253 that is used for Comb for dividing waves is identical with the cycle of the polarized light interference device 250 that is used for Comb for dividing waves, the cycle that is used for the polarized light interference device 252 of Comb for dividing waves is the twice that is used for the polarized light interference device 253 of Comb for dividing waves, just the extinction ratio than light 194a, the 194b curve of spectrum is higher through light 195a, the 195b curve of spectrum of twice filtering like this, output spectrum such as Figure 16-C1, C2.
The application example that Figure 10 is made up of two the present invention, incident ray 300 becomes the identical two-beam of polarization state 301 by polarization converter 200 among the figure.301 successively by behind λ/2 phase delay chips 201, the polarized light interference device 250 that is used for Comb for dividing waves, λ/2 phase delay chips 205, the polarized light interference device 251 that is used for Comb for dividing waves, λ/2 phase delay chips 206, divided reflective optical system 240 to be divided into two bundle 194a, 194b by crystal, 194a, 194b are divided reflective optical system 240 reflections once more by λ/2 phase delay chips 206, the polarized light interference device 251 that is used for Comb for dividing waves, λ/2 phase delay chips 205, the polarized light interference device 250 that is used for Comb for dividing waves, λ/2 phase delay chips 201 by crystal, thereby finish twice filtering.When polarization converter 200 is a structure shown in Figure 11, when crystal divides reflective optical system 240 for structure shown in Figure 12, can constitute low chromatic dispersion Comb for dividing waves device.
Figure 11 is the structural drawing and the index path of polarization converter 200.Polarization converter 200 mainly is made up of crystal polarizing beam splitter 241, λ/2 phase delay chips 242, polarization mode dispersion compensator 243 and λ/2 phase delay chips 244.
Figure 12 divides the structural drawing and the index path of reflective optical system 240 for reflecting prism type crystal.Crystal divides reflective optical system 240 mainly to be made up of λ/2 phase delay chips 247, crystal polarizing beam splitter 245, right-angle prism 246.
Figure 13 divides the structural drawing and the index path of reflective optical system 240 for plane reflection type crystal.Crystal divides reflective optical system 240 mainly to be made up of crystal polarizing beam splitter 245, reflection-type λ/4 phase delay chips 248, and wherein 248 also can be made of the Faraday crystal.
The Comb for dividing waves device is a kind of optical passive component that is used to separate the odd-even channel wavelength.The polarized light interference device of the Comb for dividing waves of forming with the inventive method, the different light-transmitting mediums that are used to transmit two-beam all can be combined by multiple medium, and promptly the transmission medium of every Shu Guang is realized according to selecting for use multiple medium to combine to the needs of temperature compensation characteristic and optical path difference.
Core of the present invention is with a polarization spectro element a branch of light to be divided into the vertical linearly polarized light of two bundle vibration planes, makes two-beam pass through different media and produces phase differential, closes optical element with polarization again and two-beam is combined into a branch of.Its protection domain relates to method itself, by the various Comb for dividing waves devices of the inventive method making, and the applied in any combination of various Comb for dividing waves devices, be not limited to the foregoing description.