CN1547047A - Tunable band-pass filter based on spatial birefringence elements - Google Patents
Tunable band-pass filter based on spatial birefringence elements Download PDFInfo
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- CN1547047A CN1547047A CNA2003101094205A CN200310109420A CN1547047A CN 1547047 A CN1547047 A CN 1547047A CN A2003101094205 A CNA2003101094205 A CN A2003101094205A CN 200310109420 A CN200310109420 A CN 200310109420A CN 1547047 A CN1547047 A CN 1547047A
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Abstract
The invention is a kind tunable band pass filter based on space double-reflecting element. The character lies in: there sets input fiber, collimating lens K (1<K<=3) cascade wedge shape media pair, off-set detector, focusing lens and output fiber along the forwards direction of the input beam, the cascade wedge shape media pair is an integrity and is connected with a motor. The invention has a large width pass bank and stop band, and high isolation rate, and the centre wavelength and the bandwidth is tunable.
Description
Technical field:
The tunable bandpass filters that the present invention relates to use in the optical system, particularly a kind of tunable bandpass filters based on the Space Double refracting element.It is mainly used in optical wavelength-division multiplex (WDM) system, in addition, also can be used for the tuned filter that all need flattened pass-band and stopband.
Background technology:
Optical band pass filter is optical wavelength-division multiplex (WDM) system, the Primary Component during optical communication measurement of correlation and other optical system are used.In wdm system, each terminal receiver all must be selected needed channel.Tunable optic filter is a kind of wavelength (or frequency) selector, and its function is from the input optical signal of a plurality of different frequencies, selects the light signal of a characteristic frequency, and very important use is arranged in wdm system.For making optimized performance, optical band pass filter should have the tunable characteristic of big smooth passband and resistance band, high isolation, centre wavelength (or frequency) and bandwidth simultaneously.
Formerly technology [1] (referring to M.Oguma, K.Jinguji, T.Kitoh, T.Shibataand A.Himeno, Electron.Lett., 36 (15), 2000, what describe in 1299-1300) is the staggered multiplex filter of a kind of light based on the slab guide trellis.It has adopted the two-stage trellis, utilize slab guide circuit technology to realize the filtering characteristic of flattened pass-band and stopband, but it does not possess the tunable characteristic of wavelength or bandwidth.
Formerly technology [2] (referring to W.Warzanskyj, F.Heismann and R.C.Alferness, Appl.Phys.Lett, 1988,53 (1), what 13-15) describe is a kind of polarization irrelevant electro-optical tuning narrow band filter that utilizes single mode waveguide to make.The smaller bandwidth of this wave filter, and only have the tunable characteristic of centre wavelength.
Formerly technology [3] (referring to W.J.Carlsen and C.F.Buhrer, Eltctron.Lett., 23 (3), 1987, what 106-107) describe is a kind of cascade birefringent polarizing interference technique that produces planarization spectral-transmission favtor function.It adopts three thickness ratios is 1: 2: 2 birefringece crystal wave plate, the spectral-transmission favtor of flattened pass-band and stopband has been realized having in position angle by the control crystal wave-plate, but the isolation of transmissivity and smooth pass band degree are not fine, and it does not have the tunable characteristic of centre wavelength or bandwidth yet.
Summary of the invention:
The technical problem to be solved in the present invention is to overcome the difficulty of above-mentioned technology formerly, a kind of tunable bandpass filters based on the Space Double refracting element is provided, this wave filter also has the tunable characteristic of centre wavelength and bandwidth in the passband with big flat width and stopband and high-isolation.
Design of the present invention is to adopt the wedge-shaped medium of cascade to structure, by controlling each wedge-shaped medium has big smooth passband and resistance band and high-isolation with realization to the angle of the position angle of medium, optical path difference that light is propagated therein and analyzer and polarizer polarization direction filtering characteristic.Wherein by change light in the optical path difference of each wedge-shaped medium centering to realize the tunable characteristic of centre wavelength and bandwidth.
Concrete technical solution of the present invention is as follows:
A kind of tunable bandpass filters based on the Space Double refracting element, the wedge-shaped medium that it is characterized in that being provided with input optical fibre, collimation lens, the polarizer, the individual cascade of K (1＜K≤3) successively along the working direction of input beam is to, analyzer, condenser lens and output optical fibre, and its cascade wedge-shaped medium is to encapsulating as a whole and linking to each other with a step motor.
Described K cascade wedge-shaped medium constitutes cascade successively, described wedge-shaped medium is to forming by two wedge-shaped medium sheets, wherein the material of first dieelctric sheet is a crystal, and optical axis is parallel to plane of crystal, vertical with the light beam incident direction, the material of second dieelctric sheet can be glass, also can be crystal, if the material crystal of second dieelctric sheet, its optical axis is identical with the light beam incident direction; When the material of second dieelctric sheet of wedge-shaped medium centering was glass material, two intrinsic refractive indexes of the refractive index of selected glass and crystal were approaching; When two dieelctric sheets of wedge-shaped medium centering were crystalline material, two intrinsic refractive indexes of the ordinary refraction index of selected second dieelctric sheet and first dieelctric sheet were approaching.
The dieelctric sheet of described wedge-shaped medium centering be shaped as the wedge shape that a base angle equals 90 °, its two all has the wedge shape of certain width, also can be the wedge shape of having only one to have certain width.
When the right number K of selected cascade wedge-shaped medium=2, two media are to being 1: 2 satisfying the optical path difference that light propagates medium centering in shape, the azimuth angle theta of first dieelctric sheet of two medium centerings
1, θ
2Angle theta with analyzer and polarizer polarization direction
PShould satisfy following combination of angles:
Combination θ
1(°) θ
2(°) θ
P(°)
1????????45?????????????-79???????????????-4
2????????45?????????????-78???????????????-4
3????????45?????????????-77???????????????-4
4????????45?????????????-76???????????????-4
5????????45?????????????-14????????????????4
6????????45?????????????-13????????????????4
7????????45?????????????-12????????????????4
8????????45?????????????-11????????????????4
When the right number K of selected cascade wedge-shaped medium=3, three media are to being 1: 2: 2 satisfying the optical path difference that light propagates medium centering in shape, the azimuth angle theta of first dieelctric sheet of three medium centerings
1, θ
2, θ
3Satisfy the following combination of angles in the literary composition:
Combination θ
1(°) θ
2(°) θ
3(°)
1?????????45??????????????-72???????????????84
2?????????45??????????????-18???????????????6
3?????????45??????????????-71???????????????83
4?????????45??????????????-19???????????????7
5?????????45??????????????-70???????????????82
6?????????45??????????????-20???????????????8
7?????????45??????????????-70???????????????83
8?????????45??????????????-20???????????????7
9?????????45??????????????-69???????????????81
10????????45??????????????-21???????????????9
11????????45??????????????-69???????????????82
12????????45??????????????-21???????????????8
Technique effect of the present invention:
The tunable bandpass filters that the present invention is based on the Space Double refracting element has realized big smooth and passband and the spectral characteristic of stopband and the tunable characteristic of centre wavelength and bandwidth of high-contrast simultaneously.With each formerly technology compare, overcome the tunable characteristic that can not realize centre wavelength and bandwidth of technology [1] formerly; Overcome the tunable characteristic that can not realize flattened pass-band and stopband and bandwidth of technology [2] formerly; Formerly isolation and the deficiency of planarization width and the tunable characteristic that can not realize centre wavelength and bandwidth of technology [3] have been overcome.
Description of drawings:
Fig. 1 is the structural representation that the present invention is based on the tunable bandpass filters embodiment of Space Double refracting element.
Fig. 2 is the variation of the distance passed through when propagating in the dieelctric sheet 11 of wedge-shaped medium centering of light beam with certain width.
Fig. 3 is the tunable performance plot of the centre wavelength of the embodiment of the invention.
Fig. 4 is the tunable performance plot of the bandwidth of the embodiment of the invention.
Embodiment:
Please consult Fig. 1 earlier, as seen from the figure, the present invention is based on the tunable bandpass filters of Space Double refracting element, the wedge-shaped medium that comprises input optical fibre 1, collimation lens 2, the polarizer 3, the individual cascade of K (1＜K≤3) to 4,5,6, step motor 7, analyzer 8, condenser lens 9 and output optical fibre 10.
K cascade wedge-shaped medium to successively by wedge-shaped medium to 4,5,6 cascades constitute.Said above-mentioned wedge-shaped medium is to forming by two wedge- shaped medium sheets 11 and 12, wherein the material of first dieelctric sheet 11 is a crystal, optical axis is parallel to plane of crystal, and vertical with the light beam incident direction, and the material of second dieelctric sheet 12 is glass or crystal (optical axis is identical with the light beam incident direction).When second dieelctric sheet 12 of wedge-shaped medium centering was glass material, two intrinsic refractive indexes of the refractive index of selected glass and crystal were approaching; When second dieelctric sheet 12 of wedge-shaped medium centering was crystalline material, two intrinsic refractive indexes of the ordinary refraction index of selected dieelctric sheet 12 and first dieelctric sheet 11 were approaching.First dieelctric sheet 11 of wedge-shaped medium centering and second dieelctric sheet 12 be shaped as the wedge shape that a base angle equals 90 °, it can all have the wedge shape of certain width for two, also can be the wedge shape of having only one to have certain width.When the right number of selected cascade wedge-shaped medium is K=2, two media are to being 1: 2 satisfying the optical path difference that light propagates medium centering in shape, the position angle of first dieelctric sheet 11 of two medium centerings, promptly fast axle of crystal or slow axis are with respect to the bias angle theta of input light polarization direction
1, θ
2Angle theta with analyzer and polarizer polarization direction
PSatisfy the combination of angles shown in the table one in the literary composition.When the right number of selected cascade wedge-shaped medium is K=3, three media are to being 1: 2: 2 satisfying the optical path difference that light propagates medium centering in shape, the combination of angles shown in the table two in the literary composition is satisfied at the position angle of first dieelctric sheet 11 of three medium centerings, and wherein analyzer is parallel with polarizer polarization direction.
Cascade wedge-shaped medium in the polarizer 3 and the analyzer 8 is to being the core of total system.First dieelctric sheet 11 (crystal) of each cascade medium centering is used to produce certain bit phase delay; The refractive index of second dieelctric sheet 12 (glass or crystal) is near the intrinsic refractive index of first dieelctric sheet 11 (crystal), the refraction that takes place at the interface at two dieelctric sheets in order to compensation light, thus make light beam right along former each medium of incident direction outgoing.At first first medium of incident is right for the right light beam of incident cascade medium, in its first dieelctric sheet 11, be broken down into two polarized lights of polarization direction mutually orthogonal, through producing certain bit phase delay behind the certain distance, then enter second dieelctric sheet 12 of this medium centering, because the refractive index of dieelctric sheet 12 is near the intrinsic refractive index of dieelctric sheet 11, thereby can ignore the refraction that light takes place at its interface, these two polarized lights are right along former this medium of direction outgoing at last.Second medium centering, because the position angle of this medium centering dieelctric sheet 11 is different with the position angle of previous medium centering dieelctric sheet 11, thereby in the right dieelctric sheet 11 of second medium, these two polarized lights are broken down into two polarized lights of polarization state mutually orthogonal again separately, produce certain bit phase delay again through behind this dieelctric sheet, equally, because the intrinsic refractive index of the refractive index of the internal dieelctric sheet 12 of this medium and dieelctric sheet 11 is approaching, light beam is right along second medium of former direction outgoing at last.Should give birth to the mutually mutually different light beam in a plurality of positions to the back common property with the medium of spline structure through a plurality of in this way, last these light beams interfere on the polarization direction of analyzer 8, wherein pass through the angle and the light optical path difference within it of position angle, analyzer and the polarizer polarization direction of the internal dieelctric sheet 11 of each medium of control, have the spectral-transmission favtor of flattened pass-band and stopband with generation, last light signal line focus lens 9 focus on and are coupled into output optical fibre 10 and export.Right step motor 7 is used to make whole cascade wedge-shaped medium to motion vertically to be connected in whole cascade wedge-shaped medium, thereby scalable light is used to realize the tuning of centre wavelength and bandwidth in the internal optical path difference of each wedge-shaped medium.
For being analyzed as follows of foregoing invention:
The planarization spectral-transmission favtor
Under the prerequisite that can ignore width of light beam, this wedge shape cascade medium pair is identical with the cascade behavior of common uniform thickness crystal wave-plate.To the thickness position place, its spectral-transmission favtor can be expressed as corresponding to certain wedge-shaped medium:
T(f)＝T
0+T
1cos(2πγ＇
1f)+T
2cos(2πγ＇
2f)+....+T
ncos(2πγ＇
nf)+....????(1)
Wherein, T
nIt is azimuth angle theta with first dieelctric sheet 11 of each wedge-shaped medium centering
1, θ
2..., θ
KRelevant coefficient, γ ＇
nTime delay γ for the dieelctric sheet 1 of each wedge-shaped medium centering of this position
1, γ
2..., γ
KSeparately or the difference of its combination in any and or and difference.Wherein, the time delay γ of the dieelctric sheet 11 of each wedge-shaped medium centering of this position
kOr frequency interval Δ f
kCan be expressed as:
Here Δ n is the birefringence of dieelctric sheet 11, d
kBe the thickness of this position dieelctric sheet 11, C is the light velocity.
The position angle by controlling each wedge-shaped medium centering dieelctric sheet 11 and the angle of thickness and analyzer and polarizer polarization direction can obtain having the spectral-transmission favtor of flattened pass-band and stopband.Following table one for when adopt two thickness ratios be 1: 2 wedge-shaped medium to the structure of cascade, greater than 2/11 cycle, isolation is not less than-during 22dB in the flat width of passband and stopband, the azimuth angle theta of each wedge-shaped medium centering dieelctric sheet 1
1, θ
2, and the angle theta of analyzer and polarizer polarization direction
pThe angle value that should satisfy.Following table two for when adopt three thickness ratios be 1: 2: 2 wedge-shaped medium to the structure of cascade, greater than 2/11 cycle, isolation is not less than-during 30dB in the flat width of passband and stopband, the azimuth angle theta of each wedge-shaped medium centering dieelctric sheet 11
1, θ
2And θ
3The angle value that should satisfy (this moment, analyzer was parallel with polarizer polarization direction, i.e. θ
p=0 °).
Table one table two
| θ 1(°) | θ 2(°) | θ p(°) |
| 45 | -79 -78 -77 -76 -14 -13 -12 -11 | -4 -4 -4 -4 4 4 4 4 |
| θ(°) | θ 2(°) | θ 3(°) |
| 45 | -72 -18 -71 -19 -70 -20 -70 -20 -69 -21 -69 -21 | 84 6 83 7 82 8 83 7 81 9 82 8 |
Tuning characteristic
By regulating the optical path difference of each wedge-shaped medium centering light, the ratio that keeps this optical path difference simultaneously is a certain value, can realize the tuning characteristic of centre wavelength and bandwidth when not influencing this spectral-transmission favtor shape.
If the wedge-shaped medium of whole cascade then can be regulated the optical path difference of each wedge-shaped medium centering light, and can keep the constant rate of this optical path difference, thereby can realize tuning characteristic motion vertically.
When firm setting in motion, the variable in distance of light process in dieelctric sheet 11 is very little, and the variation of this Time Bandwidth can be ignored and do not remember to have only centre wavelength generation translation; Along with the right continuous motion of the wedge-shaped medium of whole cascade, the variable in distance of light process in dieelctric sheet 11 is increasing, and can not ignore the variation of bandwidth this moment, and the variation of centre wavelength and bandwidth exists simultaneously.
The restriction of width of light beam
Above-mentioned characteristic all is to obtain under the condition that can ignore width of light beam, if width of light beam can not be ignored, then the thickness of light correspondence when wedge-shaped medium centering is propagated is not unique, certain deviation is promptly arranged, this will produce the influence of certain fuzzy quantity to spectral characteristic, thereby influence the performance of entire device, thereby must limit width of light beam.
Among Fig. 2, establishing width of light beam is D, and the bee-line of the light of this width process in dieelctric sheet 11 is d
i, longest distance is d
i+ δ d
i, the angle of wedge is α.By top analysis as can be known, the distance of this light beam process in dieelctric sheet 11 is from d
iTo d
i+ δ d
iThe middle variation, translation takes place respectively in then pairing centre wavelength, and the cross-talk (being isolation) in order not influence this device necessarily requires this maximal translation amount to be no more than the half width of passband.
The light beam of this width the shortest and frequency interval longest distance correspondence of process in dieelctric sheet 11 is respectively:
Then the translational movement of centre frequency is
As if the band connection frequency width is L, then being restricted to width of light beam D
When the whole wedge-shaped medium of cascade when vertically moving, d
iBetween the minor face of wedge-shaped medium sheet 11 and long limit, change d
iShould get the bond length of dieelctric sheet 11 calculates.Different wedge-shaped mediums is to the bond length difference of dieelctric sheet 11, and angle of wedge size is also different, and the restriction of final beam width is got that minimum value after calculating by (6) formula as requested.
Coarse Wavelength Division Multiplexing (CWDM) system be it is believed that it is a kind of substitute of dwdm system cheaply usually.Fig. 1 is the optical system structure synoptic diagram of the embodiment that is used for coarse wavelength division multiplexing systems of K=3 of the present invention.The material of the dieelctric sheet 11 of wherein selected each wedge-shaped medium centering is a quartz crystal, and the material of dieelctric sheet 12 is the glass of Soviet Union trade mark FK13.The ratio of the logical electrical distance of light in the right dieelctric sheet 11 of three wedge-shaped mediums is 1: 2: 2, and the position angle is respectively 45 ° ,-70 ° and 82 °.At 1.55 mu m waveband places, quartzy intrinsic refractive index is respectively: n
o=1.528, n
e=1.536, the refractive index of FK13 glass is n=1.531, and the refractive index of selected glass is very approaching with quartzy intrinsic birefringence as can be seen, and light is propagated each medium centering the direction deviation is taken place hardly.The frequency interval of the long limit correspondence of first medium centering crystal wafer is 2500GHz, i.e. wavelength interval 20nm, and bond length is 1/3rd of long limit.The length that can calculate first cumeat length of a film limit and minor face is about 14.1mm and 4.7mm, and the long limit of other two cumeat sheets and bond length are respectively the twice of first cumeat sheet.The angle of wedge of selected first cumeat is α
1=60 °, then the angle of wedge of second and third cumeat is α
241 ° of ≈, the height of three cumeat sheets is h=16.3mm.When the position angle of three crystal wafers was respectively 45 ° ,-70 ° and 82 °, the ratio that can calculate passband width and cycle was 0.202, and utilizing (6) formula can be D≤0.9mm to the width limitations of incident beam by calculating.Fig. 3 is the tunable characteristic of the centre wavelength of this wave filter, and wherein to correspond respectively to the distance of first crystal that is passed through be 14.03mm for solid line, dotted line and imaginary point line, the situation of 14.05mm and 14.07mm.Fig. 4 is the tunable characteristic of the bandwidth of this wave filter, and wherein solid line, dotted line and the imaginary point line distance that corresponds respectively to first crystal that is passed through is respectively the situation of 4.7mm, 5.4mm and 14.1mm.
Claims (5)
1, a kind of tunable bandpass filters based on the Space Double refracting element, it is characterized in that being provided with the wedge-shaped medium of input optical fibre (1), collimation lens (2), the polarizer (3), the individual cascade of K (1＜K≤3) successively to (4 along the working direction of input beam, 5,6), analyzer (8), condenser lens (9) and output optical fibre (10), its cascade wedge-shaped medium is to (4,5,6) encapsulation is as a whole and link to each other with a step motor (7).
2, tunable bandpass filters according to claim 1 is characterized in that described K cascade wedge-shaped medium is to (4,5,6) cascade constitutes successively, and described wedge-shaped medium is to (4,5,6) form by two wedge-shaped medium sheets (11,12), wherein the material of first dieelctric sheet (11) is a crystal, and optical axis is parallel to plane of crystal, and is vertical with the light beam incident direction, the material of second dieelctric sheet (12) can be glass, also can be crystal, if crystal, its optical axis is identical with the light beam incident direction; When second dieelctric sheet (12) of wedge-shaped medium centering was glass material, two intrinsic refractive indexes of the refractive index of selected glass and crystal were approaching; When second dieelctric sheet (12) of wedge-shaped medium centering when being crystalline material, two intrinsic refractive indexes of the ordinary refraction index of selected second dieelctric sheet (12) and first dieelctric sheet (11) are approaching.
3, tunable bandpass filters according to claim 2, it is characterized in that described wedge-shaped medium centering dieelctric sheet (11,12) be shaped as the wedge shape that a base angle equals 90 °, its two all has the wedge shape of certain width, also can be the wedge shape of having only one to have certain width.
4, tunable bandpass filters according to claim 2, it is characterized in that when the right number K of selected cascade wedge-shaped medium=2, two media are to being 1: 2 satisfying the optical path difference that light propagates medium centering in shape, the azimuth angle theta of first dieelctric sheet (11) of two medium centerings
1, θ
2Angle theta with analyzer and polarizer polarization direction
PShould satisfy following combination of angles:
Combination θ
1(°) θ
2(°) θ
P(°)
1?????????45????????????-79?????????????????-4
2?????????45????????????-78?????????????????-4
3?????????45????????????-77?????????????????-4
4?????????45????????????-76?????????????????-4
5?????????45????????????-14?????????????????4
6?????????45???????????-13???????????????????4
7?????????45???????????-12???????????????????4
8?????????45???????????-11???????????????????4
5, tunable bandpass filters according to claim 2, it is characterized in that when the right number K of selected cascade wedge-shaped medium=3, three media are to (4,5,6) be 1: 2: 2 satisfying light in shape in the optical path difference of medium centering propagation, the azimuth angle theta of first dieelctric sheet (11) of three medium centerings
1, θ
2, θ
3Satisfy the following combination of angles in the literary composition:
Combination θ
1(°) θ
2(°) θ
3(°)
1???????????45??????????-72????????????84
2???????????45??????????-18????????????6
3???????????45??????????-71????????????83
4???????????45??????????-19????????????7
5???????????45??????????-70????????????82
6???????????45??????????-20????????????8
7???????????45??????????-70????????????83
8???????????45??????????-20????????????7
9???????????45??????????-69????????????81
10??????????45??????????-21????????????9
11??????????45??????????-69????????????82
12??????????45??????????-21????????????8
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100383572C (en) * | 2006-05-08 | 2008-04-23 | 中国科学院上海光学精密机械研究所 | Electric control phase shift space optical hybrid |
| CN101806938A (en) * | 2010-03-17 | 2010-08-18 | 上海大学 | One-dimensional membrane cavity structure-based different-bandwidth optical interleaver |
| CN102147535A (en) * | 2011-02-25 | 2011-08-10 | 上海大学 | Polarization independent tunable optical filter based on quasi-phase matching crystal |
| CN109167131A (en) * | 2018-08-02 | 2019-01-08 | 电子科技大学 | A kind of rectangular wave inducing defecation by enema and suppository wave interference filter |
| CN110244407A (en) * | 2019-05-05 | 2019-09-17 | 深圳华中科技大学研究院 | A kind of all -fiber Birefringent Filter |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3660402B2 (en) * | 1995-08-23 | 2005-06-15 | 富士通株式会社 | Optical filter |
| DE19725720A1 (en) * | 1997-06-18 | 1998-12-24 | Alsthom Cge Alcatel | Optical isolator and wavelength multiplexer module with integrated optical isolator |
| JP3779054B2 (en) * | 1998-01-23 | 2006-05-24 | 富士通株式会社 | Variable optical filter |
| US6393176B1 (en) * | 1999-09-23 | 2002-05-21 | Avanex Corporation | Dense wavelength division multiplexer which includes a dense optical channel comb filter |
| US6421177B1 (en) * | 2000-03-03 | 2002-07-16 | Arroyo Optics, Inc. | Interleaving optical filter |
| CA2344549A1 (en) * | 2000-05-05 | 2001-11-05 | Jds Uniphase Inc. | Dispersion free optical filters |
| CN1156113C (en) * | 2002-03-08 | 2004-06-30 | 中国科学院上海光学精密机械研究所 | Birefingent cascade polarized interference old-even signal separator and its preparation method |
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2003
- 2003-12-15 CN CNB2003101094205A patent/CN100405104C/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100383572C (en) * | 2006-05-08 | 2008-04-23 | 中国科学院上海光学精密机械研究所 | Electric control phase shift space optical hybrid |
| CN101806938A (en) * | 2010-03-17 | 2010-08-18 | 上海大学 | One-dimensional membrane cavity structure-based different-bandwidth optical interleaver |
| CN102147535A (en) * | 2011-02-25 | 2011-08-10 | 上海大学 | Polarization independent tunable optical filter based on quasi-phase matching crystal |
| CN102147535B (en) * | 2011-02-25 | 2013-01-09 | 上海大学 | Polarization independent tunable optical filter based on quasi-phase matching crystal |
| CN109167131A (en) * | 2018-08-02 | 2019-01-08 | 电子科技大学 | A kind of rectangular wave inducing defecation by enema and suppository wave interference filter |
| CN109167131B (en) * | 2018-08-02 | 2020-03-27 | 电子科技大学 | Rectangular waveguide normal wave interference filter |
| CN110244407A (en) * | 2019-05-05 | 2019-09-17 | 深圳华中科技大学研究院 | A kind of all -fiber Birefringent Filter |
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| CN100405104C (en) | 2008-07-23 |
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