JPH03189628A - Optical wavelength filter - Google Patents
Optical wavelength filterInfo
- Publication number
- JPH03189628A JPH03189628A JP32917789A JP32917789A JPH03189628A JP H03189628 A JPH03189628 A JP H03189628A JP 32917789 A JP32917789 A JP 32917789A JP 32917789 A JP32917789 A JP 32917789A JP H03189628 A JPH03189628 A JP H03189628A
- Authority
- JP
- Japan
- Prior art keywords
- mode
- signal light
- wavelength
- separated
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 28
- 238000006243 chemical reaction Methods 0.000 claims abstract description 9
- 229910052729 chemical element Inorganic materials 0.000 abstract 1
- 238000000926 separation method Methods 0.000 description 16
- 230000010287 polarization Effects 0.000 description 6
- 230000008878 coupling Effects 0.000 description 4
- 238000010168 coupling process Methods 0.000 description 4
- 238000005859 coupling reaction Methods 0.000 description 4
- 239000000758 substrate Substances 0.000 description 3
- 244000126211 Hericium coralloides Species 0.000 description 2
- 230000013011 mating Effects 0.000 description 2
- 239000000470 constituent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/12007—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29344—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by modal interference or beating, i.e. of transverse modes, e.g. zero-gap directional coupler, MMI
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29346—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by wave or beam interference
- G02B6/2935—Mach-Zehnder configuration, i.e. comprising separate splitting and combining means
- G02B6/29352—Mach-Zehnder configuration, i.e. comprising separate splitting and combining means in a light guide
- G02B6/29353—Mach-Zehnder configuration, i.e. comprising separate splitting and combining means in a light guide with a wavelength selective element in at least one light guide interferometer arm, e.g. grating, interference filter, resonator
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
- G02B6/29395—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device configurable, e.g. tunable or reconfigurable
Abstract
Description
【発明の詳細な説明】 （産業上の利用分野） この発明は光波長フィルタに間する。[Detailed description of the invention] (Industrial application field) The present invention relates to optical wavelength filters.
（従来の技術）
従来、波長多重の光信号から所定の分離波長の光を分離
する光波長フィルタとして、例えば文献Ｉ：Ａｐｐｌｉ
ｅｄ Ｐｈｙｓｉｃｓ Ｌｅｔ−ｔｅｒｓ（アプラ
イド フィジクス レターズ）Ｖｏｌ、５３ Ｎｏ、
１１ ｐ、１３〜１４に開示されているものがある。(Prior Art) Conventionally, as an optical wavelength filter that separates light of a predetermined separation wavelength from a wavelength-multiplexed optical signal, for example, Document I: Appli
ed Physics Let-ters (Applied Physics Letters) Vol. 53 No.
11 p., 13-14.
第２図はこの従来の光波長フィルタの構成を概略的に示
す斜視図である。FIG. 2 is a perspective view schematically showing the structure of this conventional optical wavelength filter.
同図にも示すように、従来の光波長フィルタはＸカット
し１Ｎｂ０３基板１０に並列させて設けた導波路１２及
び１４と、これら導波路１２．１４の入力側及び出力側
に設けた入力側偏波分離素子１６及び出力側偏波分離素
子１８と、これら分離素子１６．１８の間に配置して導
波路１２に設けたＴＭ−ＴＥモード変換器２０及び導波
路１４に設けたＴＭ−ＴＥモード変換器２２とから成る
。分離素子１６、］８は反転Δβ電極を備えた２Ｘ２方
向性結合器でありＴＥ波に対して交差状態及びＴＭ波に
対して直進状態で動作する。また変換器１８．２ｏは特
定の波長（この波長が分離波長となる）のＴＭ波をＴＥ
波に及びＴＥ波をＴＭ波に変換するものであり、分離波
長を可変設定できる構成となっている。As shown in the figure, the conventional optical wavelength filter has X-cut waveguides 12 and 14 provided in parallel on a 1Nb03 substrate 10, and input sides provided on the input and output sides of these waveguides 12 and 14. Polarization separation element 16 and output side polarization separation element 18, a TM-TE mode converter 20 provided in the waveguide 12 between these separation elements 16 and 18, and a TM-TE provided in the waveguide 14. It consists of a mode converter 22. The separation elements 16, ]8 are 2×2 directional couplers with inverted Δβ electrodes, and operate in a crossing state for TE waves and in a straight forward state for TM waves. In addition, the converter 18.2o converts the TM wave of a specific wavelength (this wavelength becomes the separation wavelength) into TE.
It converts TE waves into TM waves, and has a configuration in which the separation wavelength can be variably set.
このような構成の従来フィルタは、導波路１４の入力ポ
ートａから光を入力すると、分離波長のＴＭ波及びＴＥ
波を導波路１２の出力ポートｂから出力し、非分離波長
のＴＭ波及びＴＥ波を導波路１４の出力ポートＣから出
力し、従って波長多重の信号光から特定波長の信号光を
分離することかできる。In the conventional filter having such a configuration, when light is inputted from the input port a of the waveguide 14, the TM wave and the TE wave of the separated wavelength are separated.
wave from the output port b of the waveguide 12, output TM waves and TE waves of non-separated wavelengths from the output port C of the waveguide 14, and thus separate the signal light of a specific wavelength from the wavelength-multiplexed signal light. I can do it.
（発明か解決しようとする課題）
しかしなから上述した従来の光波長フィルタは、偏波分
離素子（反転へβ電極を備える方向性結合器）を用いて
いるので電極数が多くなり構成が複雑になるという問題
点かあった。(Problem to be solved by the invention) However, since the conventional optical wavelength filter described above uses a polarization separation element (a directional coupler with a β electrode for inversion), the number of electrodes is large and the configuration is complicated. There was a problem with becoming.
この発明の目的は、上述した従来の問題点を解決するた
め、３ｄＢカブラを利用した光波長フィルタを提供する
ことにある。An object of the present invention is to provide an optical wavelength filter using a 3 dB coupler in order to solve the above-mentioned conventional problems.
（課題を解決するための手段）
この目的を達成するため、この発明の光波長フィルタは
、入力した波長多重の信号光を分離波長の信号光と非分
離波長の信号光とに分離して出力する光波長フィルタに
おいて、信号光を偶モード及び奇モードのいずれかの状
態にして出力する第一素子、及び、第一素子からの信号
光を分岐して出力する第二素子から成る入力側３ｄＢカ
ブラと、第二素子の出力毎に設けられ、第二素子からの
信号光のうち分離波長の信号光に対しＴＭ−ＴＥモード
変換を行なうモード変換器と、各モード変換器からの信
号光を合流し合流した信号光を出力する第三素子、及び
、第三素子からの信号光を入力し偶モードの信号光と奇
モードの信号光とをそれぞれ分離して出力する第四素子
から成る出力側３ｄＢカブラとを備えて成ることを特徴
とする。(Means for Solving the Problems) In order to achieve this object, the optical wavelength filter of the present invention separates input wavelength-multiplexed signal light into signal light of a separated wavelength and signal light of a non-separated wavelength, and outputs the separated wavelength signal light. In the optical wavelength filter, the input side consists of a first element that outputs the signal light in either an even mode or an odd mode, and a second element that branches the signal light from the first element and outputs it. a mode converter that is provided for each output of the second element and performs TM-TE mode conversion on the signal light of the separated wavelength among the signal lights from the second element; An output consisting of a third element that merges and outputs the combined signal light, and a fourth element that inputs the signal light from the third element and separates and outputs even mode signal light and odd mode signal light, respectively. It is characterized by comprising a side 3 dB doubler.
（作用）
このような構成の光波長フィルタによれば、入力側３ｄ
Ｂカブラは７Ｍモード及びＴＥモードの成分に分離した
状態の信号光を、偶モード又は奇モードのいずれかの状
態にしそして信号光を分岐して出力する。(Function) According to the optical wavelength filter having such a configuration, the input side 3d
The B coupler converts the signal light separated into 7M mode and TE mode components into an even mode or an odd mode, and branches the signal light and outputs it.
入力側３ｄＢカプラの各出力毎に設けられたモード変換
器はそれぞれ分岐した信号光を入力する。モード変換器
は、入力した信号光の波長が分離波長であれば信号光の
モードを７ＭモードからＴＥモードに変換し或はＴＥモ
ードから７Ｍモードに変換するＴＭ−ＴＥモード変換を
行なう、入力した信号光が非分離波長を有する場合には
このようなＴＭ−ＴＥモード変換を行なわない。The mode converters provided for each output of the 3 dB coupler on the input side input the branched signal lights, respectively. If the wavelength of the input signal light is the separation wavelength, the mode converter converts the mode of the signal light from 7M mode to TE mode, or performs TM-TE mode conversion to convert from TE mode to 7M mode. If the signal light has a non-separated wavelength, such TM-TE mode conversion is not performed.
そして出力側３ｄＢカプラは、各モード変換器からの信
号光を合流し、この合流した信号光を偶モードの信号光
と奇モードの信号光とにそれぞれ分離して出力する。こ
のとき偶モードの信号光（よ非分離波長を有し、奇モー
ドの信号光は分離波長を有するので、波長多重の信号光
から所定の分離波長の信号光を分離して出力できる。The output side 3 dB coupler combines the signal lights from each mode converter, separates the combined signal lights into even mode signal light and odd mode signal light, and outputs the separated signals. At this time, since the even mode signal light (has a non-separable wavelength) and the odd mode signal light has a separation wavelength, it is possible to separate and output signal light of a predetermined separation wavelength from the wavelength-multiplexed signal light.
（実施例）
以下、図面１ｇ照し、この発明の実施例につき説明する
。尚、図面はこの発明が理解できる程度に、従って各構
成成分の形状、寸法及び配設位置を概略的に示してある
にすぎず、従ってこの発明の構造に限定するものではな
い。(Example) Hereinafter, an example of the present invention will be described with reference to drawing 1g. It should be noted that the drawings merely show the shapes, dimensions and arrangement positions of each constituent component schematically to the extent that the present invention can be understood, and therefore are not intended to limit the structure of the present invention.
第１図はこの発明の実施例の構成を概略的に示す平面図
である。FIG. 1 is a plan view schematically showing the configuration of an embodiment of the present invention.
この実施例の光波長フィルタは、入力ポート２４又は２
６から入力した波長多重の信号光を分離波長の信号光と
非分離波長の信号光とに分離してそれぞれ異なる出力ポ
ート３ｏ及び２８から出力するものであって、入力側３
ｄＢカブラ３２、モード変換器３４．３６及び出力側３
ｄＢカブラ３８から成る。The optical wavelength filter of this embodiment has input port 24 or 2.
The wavelength-multiplexed signal light input from the input side 3 is separated into a signal light with a separated wavelength and a signal light with a non-separated wavelength, and outputted from different output ports 3o and 28, respectively.
dB coupler 32, mode converter 34, 36 and output side 3
It consists of dB coupler 38.
入力側３ｄＢカブラ３２は、信号光を偶モード及び奇モ
ードのいずれかの状態にして出力する第一素子４０、及
び、この素子４０からの信号光を分岐して出力する第二
素子４２から成る。モ−ド変換器３４．３６はそれぞれ
第二素子４２＠出力毎に設けられ第二素子４２からの信
号光のうち分離波長の信号光に対しＴＭ−ＴＥモード変
換を行なう。The input side 3 dB coupler 32 consists of a first element 40 that outputs the signal light in either an even mode or an odd mode, and a second element 42 that branches the signal light from this element 40 and outputs it. . The mode converters 34 and 36 are provided for each output of the second element 42 and perform TM-TE mode conversion on the signal light of the separated wavelength among the signal lights from the second element 42.
出力側３ｄＢカツプ３８は、各モード変換器３４．３６
からの信号光を合流し合流した信号光を出力する第三素
子４４、及び、この素子４４からの信号光を入力し偶モ
ードの信号光と奇モードの信号光とをそれぞれ分離して
出力する第四素子４６から成る。The output side 3dB cup 38 is connected to each mode converter 34.36.
A third element 44 which combines the signal lights from the elements and outputs the combined signal light, and inputs the signal light from this element 44 and separates and outputs the even mode signal light and the odd mode signal light, respectively. It consists of a fourth element 46.
以下、より詳細にこの実施例につき説明する。This embodiment will be explained in more detail below.
この実施例では、基板４７として常光−異常光の変換を
行なえる電気光学係数を有する基板例えばＸカットＬｉ
Ｎｔ）０３基板を用い、この基板４７に２×２入力端３
ｄＢカプラ３２と、２×２出力側３ｄＢカブラ３８と、
対応するカブラ３２の出力及びカブラ３８の入力をそれ
ぞれ結合するモード変換器３４．３６を設ける。In this embodiment, the substrate 47 is a substrate having an electro-optic coefficient capable of converting ordinary light to extraordinary light, such as an X-cut Li.
Nt)03 board is used, and 2x2 input terminal 3 is connected to this board 47.
dB coupler 32, 2×2 output side 3dB coupler 38,
Mode converters 34, 36 are provided which couple the output of the corresponding coupler 32 and the input of the coupler 38, respectively.
入力側３ｄＢカブラ３２は２×１第一素子４０の出力と
１×２第二素子４２の入力とを結合して成る。第一素子
４０を、偶モード光を励起する導波路幅の広い導波路４
８の一方の端部と、奇モード光を励起する導波路幅の狭
い導波路５０の一方の端部とを結合して構成した２×１
非対称分岐とし、また第二素子４２を、導波路幅の等し
い導波路５２及び５４の一方の端部を互いに結合して構
成した１×２パワ一分岐とする。The input side 3 dB coupler 32 is formed by combining the output of a 2×1 first element 40 and the input of a 1×2 second element 42. The first element 40 is a waveguide 4 with a wide waveguide width that excites even mode light.
8 and one end of a waveguide 50 with a narrow waveguide width that excites odd mode light.
The second element 42 is a 1×2 power branch formed by coupling one end of waveguides 52 and 54 with the same waveguide width to each other.
また出力側３（ＩＳカプラ３８は２×１第ヨ素子４４の
出力と１ｘ２第四素子４６の入力とを結合して成る。第
三素子４４を導波路幅の等しい導波路５６及び５８の一
方の端部を互いに結合して構成した２×１パワ一合流分
岐とし、第四素子４６を偶モードを励起する導波路６０
及び奇モードを励起する導波路６２の一方の端部を互い
に結合して構成したＩＸ２非対称分岐とする。Further, the output side 3 (IS coupler 38 is formed by coupling the output of the 2×1 first element 44 and the input of the 1×2 fourth element 46. The third element 44 is connected to one of the waveguides 56 and 58 having the same waveguide width. The ends of the waveguide 60 are connected to each other to form a 2×1 power convergence branch, and the fourth element 46 is a waveguide 60 that excites an even mode.
and one end of the waveguide 62 that excites the odd mode are coupled together to form an IX2 asymmetric branch.
モード変換器３４は第二素子４２の一方の導波路５２及
び第三素子４４の一方の導波路５６を結合する導波路６
４と、互いに指合するくし歯状電極６６及び６８とから
成り、またモード変換器３６は第二素子４２の他方の導
波路５４及び第三素子４４の他方の導波路５８を結合す
る導波路７０と、互いに指合するくし歯状電極７２及び
７４とから成る。導波路６４及び７０は互いに平行に配
Ｍ′２！れている。電極６６及び６８の指合するくし歯
部分の配設ピッチ（周期）及び電極７２及び７４の指合
するくし歯部分の配設ピッチ（周期）を等ピッチへとし
ている。The mode converter 34 is a waveguide 6 that couples one waveguide 52 of the second element 42 and one waveguide 56 of the third element 44.
4 and comb-like electrodes 66 and 68 that point to each other, and the mode converter 36 is a waveguide that couples the other waveguide 54 of the second element 42 and the other waveguide 58 of the third element 44. 70, and interdigitated comb-like electrodes 72 and 74. The waveguides 64 and 70 are arranged parallel to each other M'2! It is. The arrangement pitch (period) of the mating comb tooth portions of the electrodes 66 and 68 and the arrangement pitch (period) of the mating comb tooth portions of the electrodes 72 and 74 are made equal.
この実施例の光波長フィルタの入力ポート２４又は２６
から波長多重の信号光を入力すると各波長の信号光はそ
れぞれＴＭモード及びＴＥモードの２成分に分離した状
態で入力ポート２４．２６から出力ポート２８．３０ま
で導波する。Input port 24 or 26 of the optical wavelength filter of this embodiment
When wavelength-multiplexed signal light is input from the input port 24.26, the signal light of each wavelength is separated into two components of TM mode and TE mode and guided from the input port 24.26 to the output port 28.30.
また入力ポート２４又は２６から入力した波長多重の信
号光は第一分岐４０により偶モード及び奇モードのいず
れか一方の状態にされて第二素子４２に入力する。クロ
ストークを低減するため理想的には信号光を第二素子４
２によりそれぞれ等しい光パワー及び等しい位相で分岐
し各モード変換器３４．３６に入力するのが好ましい、
各モード変換器３４．３６では、分離波長を有する信号
光のみＴＭモードからＴＥモードへ或はＴＥモードから
ＴＭモードへ変換される。Further, the wavelength-multiplexed signal light inputted from the input port 24 or 26 is converted into either an even mode or odd mode state by the first branch 40 and inputted to the second element 42 . Ideally, the signal light should be transferred to the second element 4 to reduce crosstalk.
2 with equal optical power and equal phase and input into each mode converter 34, 36,
In each mode converter 34, 36, only the signal light having the separated wavelength is converted from the TM mode to the TE mode or from the TE mode to the TM mode.
各モード変換器３４．３６がらの信号光は第三素子４４
により合流されるが、クロストーク低減のため理想的に
は各モード変換器３４．３６の出力点における各信号光
の位相差が保存されたままの状態で信号光が合流される
のが好ましい。The signal light from each mode converter 34, 36 is sent to the third element 44.
However, in order to reduce crosstalk, it is ideal that the signal lights are combined while the phase difference of each signal light at the output point of each mode converter 34, 36 is maintained.
この合流した信号光のうち奇モードの信号光は分離波長
を有し及び偶モードの信号光は非分離波長を有するので
、第四素子３８に入力した分離波長の信号光は出力ポー
ト３０から及び非分離波長の信号光は出力ポート２８か
ら出力する。Among the combined signal lights, the odd mode signal light has a separated wavelength, and the even mode signal light has a non-separated wavelength. The signal light of the non-separated wavelength is output from the output port 28.
次に動作原理につき説明する。モード変換器３４及び３
６におけるモード変換の様子は、結合方程式を解いて得
られる式（１）及び（２）により表せる。これら（１）
及び（２）式を次頁に示す、但し、ε、Ｐ及びεｐ＋は
導波路ｉ （ｉ＝６４又は７０）の始点ＰにおけるＴＭ
波（信号光のＴＭモード成分）及びＴＥ波（信号光のＴ
Ｅモード成分）の光パワー ε、０及びε１０°は導波
路ｉの終点ＱにあけるＴＭ波及びＴＥ波の光パワーγは
モード変換結合係数、ｊは虚数単位、及びｔは導波路ｉ
に沿う方向における始点Ｐがらの光の伝搬距離である。Next, the principle of operation will be explained. Mode converters 34 and 3
The state of mode conversion in 6 can be expressed by equations (1) and (2) obtained by solving the coupling equation. These (1)
and (2) are shown on the next page, where ε, P and εp+ are the TM at the starting point P of waveguide i (i=64 or 70)
wave (TM mode component of signal light) and TE wave (T mode component of signal light)
E mode component) optical power ε, 0 and ε10° are the optical powers of the TM wave and TE wave at the end point Q of waveguide i, γ is the mode conversion coupling coefficient, j is the imaginary unit, and t is the waveguide i
It is the propagation distance of light from the starting point P in the direction along .
また６は６＝ＴＩ（（Δｎ／λ）＝（１／△））（但し
、ΔｎはＴＭ波及びＴＥ波の屈折率差、λは光の波長及
び△はくし歯状電極１
１
＼−−−／ ＼−−−）第一素子
４０の導波路４８から信号光を入力した場合、信号光は
この導波路４８で偶モードとなり第二素子４２に入力す
る。そして第二素子４２により分岐され、クロストーク
低減のため同位相及び等しい光パワーで信号光が各モー
ド変換器３４．３６に入力し、分離波長を有する信号光
は変換器３４．３６によりＴＭ−ＴＥ変換される。Also, 6 is 6 = TI ((Δn/λ) = (1/△)) (where Δn is the refractive index difference between the TM wave and the TE wave, λ is the wavelength of light, and Δ is the comb-shaped electrode 1 1 \-- -/\---) When signal light is input from the waveguide 48 of the first element 40, the signal light becomes an even mode in this waveguide 48 and is input to the second element 42. The signal lights are then branched by the second element 42 and input into each mode converter 34.36 with the same phase and equal optical power to reduce crosstalk, and the signal lights with separated wavelengths are converted into TM- TE converted.
変換器３４．３６から出力した信号光は、クロストーク
低減のため変換器３４．３６の出力点における位相差を
保存したまま第三素子４４の合流点Ｃで合流する。The signal lights output from the converters 34, 36 merge at the confluence point C of the third element 44 while preserving the phase difference at the output point of the converters 34, 36 to reduce crosstalk.
合流点Ｃにおける、偶モードの信号光のＴＭ及びＴＥモ
ード成分の光パワーε、Ｃ及びε、Ｃ′を次頁（３）式
にまた奇モードの信号光のＴＭ及びＴＥモート成分の光
パワーε。Ｃ及びε。Ｃ′ヲ次頁の（４）式に示す、但
し、ε６４Ｐ＝ε７゜Ｐ、εｓａｐ“＝ε７゜Ｐｏとし
て（３）及び（４）式を求めた。またε、Ｐ及びε、Ｐ
ｏは始点Ｐにおゆる偶モードの信号光のＴＭ及びＴＥモ
ード成分の光パワー、及びε。Ｐ及びε。Ｐｏは始点Ｐ
における奇モードの信号光のＴＭ及びＴＥモード成分の
光パワーである。尚、電極６６．６８．７２．７４の電
極長をしとすれば、（３）及び（４）式においてｔ＝Ｌ
である。At the confluence point C, the optical powers ε, C and ε, C' of the TM and TE mode components of the even mode signal light can be expressed as equations (3) on the next page, and the optical powers of the TM and TE mode components of the odd mode signal light can be expressed as: ε. C and ε. C′ is shown in equation (4) on the next page. However, equations (3) and (4) were obtained by setting ε64P=ε7゜P and εsap"=ε7゜Po. Also, ε, P and ε, P
o is the optical power of the TM and TE mode components of the even mode signal light at the starting point P, and ε. P and ε. Po is the starting point P
is the optical power of the TM and TE mode components of the odd mode signal light in . In addition, if the electrode length of the electrode 66, 68, 72, 74 is assumed, then in equations (3) and (4), t=L
It is.
信号光の波長λが非分離波長のとき６→（１）となり、
従って次式（３）、（４）式より（５ａ）、（５ｂ）式
が得られる。これがため合流点Ｃでは非分離波長の信号
光のＴＭ及びＴＥモード成分は偶モードのみとなり、従
って非分離波長の信号光のＴＭ及びＴＥモード成分を第
四素子４６の導波路６０を介し出力ポート２８から出力
させることができる。When the wavelength λ of the signal light is a non-separable wavelength, 6 → (1),
Therefore, equations (5a) and (5b) are obtained from the following equations (3) and (4). Therefore, at the confluence point C, the TM and TE mode components of the signal light of the non-separated wavelength are only even modes, and therefore the TM and TE mode components of the signal light of the non-separated wavelength are passed through the waveguide 60 of the fourth element 46 to the output port. It can be output from 28.
＋＋
１
＼Ｎ−一、−−ｌ
また信号光の波長λが分離波長のときλ＝Δｎ・△とな
り、このとき６＝０４ので次式（６）及び（７）が得ら
れる。尚、６＝Ｏのときβ＝γであり、また（６）及び
（７）式においてｔ＝Ｌである。++ 1 \N-1, -l Further, when the wavelength λ of the signal light is the separation wavelength, λ=Δn·Δ, and in this case, 6=04, so the following equations (6) and (7) are obtained. Note that when 6=O, β=γ, and t=L in equations (6) and (7).
従って（６）及び（７）式よりβ・ｔ＝γ・Ｌ＝（，２
ｍ＋１） ・ （Ｔ［／２）（但し、ｍ＝ｏ、１．２
、・・・・・・）とすれば、合流点Ｃにおいて分離波長
の信号光のＴＭ及びＴＥモード成分を奇モードのみとす
ることができる。γをγ・Ｌ＝ （２ｍ＋１）・（Ｔ［
／２）を満足するように電極６６．６８．７２．７４の
印加電圧を制御することによって、分離波長λ＝Δｎ・
△を有する信号光のＴＭ及びＴＥモード成分を第四素子
４６の導波路６２を介し出力ポートロ２がら出力させ、
従って分離波長の信号光と非分離波長の信号とを偏光依
存性なく分離して出力させることができる。Therefore, from equations (6) and (7), β・t=γ・L=(,2
m+1) ・(T[/2) (However, m=o, 1.2
. γ is γ・L= (2m+1)・(T[
/2) By controlling the voltage applied to the electrodes 66,68,72,74, the separation wavelength λ=Δn・
TM and TE mode components of the signal light having Δ are outputted from the output port 2 through the waveguide 62 of the fourth element 46,
Therefore, it is possible to separate and output the signal light of the separation wavelength and the signal of the non-separation wavelength without polarization dependence.
この発明は上述した実施例にのみ限定されるものではな
く、従って各構成成分の構成、形状、寸法、配設位置、
形成材料、数値的条件及びそのほかの条件を任意好適に
変更できる０例えば第一素子を偶モード光を励起するひ
とつの導波路のみから、或は奇モード光を励起するひと
つの導波路のみから構成するようにしてもよい。The present invention is not limited only to the embodiments described above, and therefore the configuration, shape, size, arrangement position, etc. of each component,
Forming materials, numerical conditions, and other conditions can be changed as desired.For example, the first element is configured from only one waveguide that excites even mode light, or only one waveguide that excites odd mode light. You may also do so.
（発明の効果）
上述した説明からも明らかなように、この発明の光波長
フィルタによれば、入力側及び出力側３ｄＢカプラを用
いるので、入力側及び出力側偏波分離素子に反転ΔＢ電
極型の方向性結合器を用いていた従来の光波長フィルタ
と比較して、電極構成が簡単になる。しがも、波長多重
の信号光から非分離波長の信号光と分離波長の信号光と
を偏光依存性なく分離することができる。(Effects of the Invention) As is clear from the above description, according to the optical wavelength filter of the present invention, since 3 dB couplers are used on the input side and the output side, the polarization separation elements on the input side and the output side are of the inverted ΔB electrode type. Compared to conventional optical wavelength filters that use directional couplers, the electrode configuration is simplified. However, it is possible to separate the wavelength-multiplexed signal light into the non-separated wavelength signal light and the separated wavelength signal light without polarization dependence.
第１図はこの発明の実施例の構成を概略的に示す平面図
、
第２図は従来の光波長フィルタの構成を概略的に示す斜
視図である。
３２・・・入力側３ｄＢカプラ
３４．３６・・・モード変換器
３８・・・出力側３ｄＢカプラ
４ｏ・・・第一素子、 ４２−・・第二素子４４・・
・第三素子、 ４６・・・第四素子。FIG. 1 is a plan view schematically showing the structure of an embodiment of the present invention, and FIG. 2 is a perspective view schematically showing the structure of a conventional optical wavelength filter. 32... Input side 3dB coupler 34. 36... Mode converter 38... Output side 3dB coupler 4o... First element, 42-... Second element 44...
- Third element, 46... Fourth element.
Claims (1)
非分離波長の信号光とに分離して出力する光波長フィル
タにおいて、 信号光を偶モード及び奇モードのいずれかの状態にして
出力する第一素子、及び、該第一素子からの信号光を分
岐して出力する第二素子から成る入力側３ｄＢカプラと
、 前記第二素子の出力毎に設けられ、前記第二素子からの
信号光のうち分離波長の信号光に対しＴＭ−ＴＥモード
変換を行なうモード変換器と、各モード変換器からの信
号光を合流し合流した信号光を出力する第三素子、及び
、該第三素子からの信号光を入力し偶モードの信号光と
奇モードの信号光とをそれぞれ分離して出力する第四素
子から成る出力側３ｄＢカプラとを備えて成ることを特
徴とする光波長フィルタ。(1) In an optical wavelength filter that separates input wavelength-multiplexed signal light into signal light with a separated wavelength and signal light with a non-separated wavelength and outputs the separated signal light, the signal light is placed in either an even mode or an odd mode. an input side 3 dB coupler consisting of a first element that outputs, and a second element that branches and outputs the signal light from the first element; and a 3 dB coupler on the input side that is provided for each output of the second element and a mode converter that performs TM-TE mode conversion on signal lights of separated wavelengths among the signal lights; a third element that combines signal lights from each mode converter and outputs the combined signal lights; An optical wavelength filter comprising an output-side 3 dB coupler comprising a fourth element that inputs signal light from the element, separates even mode signal light and odd mode signal light, and outputs the separated signals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32917789A JPH03189628A (en) | 1989-12-19 | 1989-12-19 | Optical wavelength filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32917789A JPH03189628A (en) | 1989-12-19 | 1989-12-19 | Optical wavelength filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03189628A true JPH03189628A (en) | 1991-08-19 |
Family
ID=18218511
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32917789A Pending JPH03189628A (en) | 1989-12-19 | 1989-12-19 | Optical wavelength filter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03189628A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012203283A (en) * | 2011-03-28 | 2012-10-22 | Sumitomo Osaka Cement Co Ltd | Optical modulator |
-
1989
- 1989-12-19 JP JP32917789A patent/JPH03189628A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012203283A (en) * | 2011-03-28 | 2012-10-22 | Sumitomo Osaka Cement Co Ltd | Optical modulator |
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