JPS6325604A - Optical circuit device - Google Patents
Optical circuit deviceInfo
- Publication number
- JPS6325604A JPS6325604A JP16915786A JP16915786A JPS6325604A JP S6325604 A JPS6325604 A JP S6325604A JP 16915786 A JP16915786 A JP 16915786A JP 16915786 A JP16915786 A JP 16915786A JP S6325604 A JPS6325604 A JP S6325604A
- Authority
- JP
- Japan
- Prior art keywords
- light
- filter
- wavelength
- angle
- optical path
- 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 95
- 239000004065 semiconductor Substances 0.000 abstract description 11
- 239000000835 fiber Substances 0.000 abstract description 9
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 abstract description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract 2
- 229910052681 coesite Inorganic materials 0.000 abstract 1
- 229910052906 cristobalite Inorganic materials 0.000 abstract 1
- 239000000377 silicon dioxide Substances 0.000 abstract 1
- 235000012239 silicon dioxide Nutrition 0.000 abstract 1
- 229910052682 stishovite Inorganic materials 0.000 abstract 1
- 229910052905 tridymite Inorganic materials 0.000 abstract 1
- 230000005540 biological transmission Effects 0.000 description 11
- 230000000694 effects Effects 0.000 description 10
- 230000002238 attenuated effect Effects 0.000 description 6
- 238000003780 insertion Methods 0.000 description 5
- 230000037431 insertion Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000013307 optical fiber Substances 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 230000002457 bidirectional effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
Landscapes
- Optical Filters (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、光通信において波長ごとに異なる光信号を
伝送するための光波長多重通信に用いる光回路装置に関
するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical circuit device used in optical wavelength division multiplexing communication for transmitting different optical signals for each wavelength in optical communication.
光波長多重通侶を行なうためには、光を異なる波長ごと
に分離せしめる光回路(以下光分波回路と呼ぶ)が必要
である。光を波長ごとに分離するには、干渉フィルタを
用いる方法、グレーティングを用いる方法、プリズムを
用いる方法等があるが、現在良く用いられているのは、
干渉フィルタを用いる方法である。例えば、第4図は、
昭和60年度電子通信学会総合全国大会講演番号262
1に示された従来の光分波回路の構成図であり、(1)
は波長λAの半導体レーザ、(2)はGe −APD
、 +31は光ファイバ、(4)は波長2人の光を透過
し波長λBの光を反射する干渉膜フィルタ、 ls+l
、 f’Ji2波長λ9の光を反射し、波長λBの光を
透過する干渉膜フィルタで光路に対しフィルタ法線が1
5度をなすよう挿入されている。+61. (71,+
81は光をコリメート又は集光させるためのレンズ、
+91. (1111はプリズム、αBはミラーである
。又図中矢印付きの実線及び破線は光路を示す。次に動
作について説明する。半導体レーザ(1)より出射した
波長λAの光はレンズ(6)によって平行光束に変換さ
れ干渉膜フィルタ(4)を透過し直進しレンズ(7)に
よってファイバ(31に送出される。一方ファイバ(3
)より入射した波長λ8の光はレンズ(7)によって平
行光束に変換され、干渉膜フィルタ(91によって反射
されプリズム0α内を1方に進み、ミラーαυによって
反射され干接フィルタ膜フィルタi5j+、 +521
を透過しレンズ(8)によってG eAP D (21
H’M上へ集光される。このようにしてこの光回路は、
波長λAの光をファイバへ送出するとともに波長λ8の
光をファイバよりGe−APDへ導く働きをなし2波長
多重の双方向伝送を可能にするものである。ここでG
e−APDの前に挿入されている干渉膜フィルタ+5+
1. (521は。In order to perform optical wavelength multiplexing, an optical circuit (hereinafter referred to as an optical demultiplexing circuit) that separates light into different wavelengths is required. There are methods to separate light into wavelengths, such as using interference filters, gratings, and prisms, but the most commonly used methods are:
This method uses an interference filter. For example, in Figure 4,
1985 IEICE General National Conference Lecture No. 262
1 is a configuration diagram of the conventional optical demultiplexing circuit shown in FIG.
is a semiconductor laser with wavelength λA, (2) is Ge-APD
, +31 is an optical fiber, (4) is an interference film filter that transmits light of two wavelengths and reflects light of wavelength λB, ls+l
, f'Ji2 An interference film filter that reflects light with wavelength λ9 and transmits light with wavelength λB, and the filter normal to the optical path is 1.
They are inserted to form a fifth degree. +61. (71,+
81 is a lens for collimating or condensing light;
+91. (1111 is a prism, αB is a mirror. In addition, solid lines and broken lines with arrows in the figure indicate optical paths. Next, the operation will be explained. The light with wavelength λA emitted from the semiconductor laser (1) is passed through the lens (6). It is converted into a parallel light beam, passes through an interference film filter (4), travels straight, and is sent out to a fiber (31) by a lens (7).
) is converted into a parallel beam by the lens (7), reflected by the interference film filter (91), propagates in one direction within the prism 0α, reflected by the mirror αυ, and passes through the tangent filter film filter i5j+, +521
G eAP D (21
The light is focused onto H'M. In this way, this optical circuit
It functions to send out the light with wavelength λA to the fiber and guide the light with wavelength λ8 from the fiber to the Ge-APD, thereby enabling bidirectional transmission of two-wavelength multiplexing. G here
Interference film filter +5+ inserted in front of e-APD
1. (521 is.
例えば半導体レーザ(1)からでた波長λ9の光が反射
・散乱等によってこのフィルタへ入射した場合。For example, when light with a wavelength λ9 emitted from the semiconductor laser (1) enters this filter due to reflection, scattering, etc.
これを除去するために挿入されているもので波長λBに
対しては透明で波長λ9に対しては反射となるよう選ば
れるものである。It is inserted to remove this, and is selected so that it is transparent for the wavelength λB and reflective for the wavelength λ9.
しかしながら、従来の装置は以上のように構成されてい
たので9次のような問題点があった。即ち波長λ8を透
過し波長λAを反射する干渉膜フィルタ1511 、
f52+に何らかの雑因で波長λAの光が。However, since the conventional device was configured as described above, it had the following problems. That is, an interference film filter 1511 that transmits the wavelength λ8 and reflects the wavelength λA;
Due to some miscellaneous factors, light of wavelength λA was detected on f52+.
所定の角度以外の入射角をもってフィルタ(511,[
521に入射したときに、フィルタ(511,fs21
で十分除去されない場合があった。Filter (511, [
521, the filter (511, fs21
In some cases, it was not removed sufficiently.
?l’S5図はこの間の事情を説明するための図でフィ
ルタ(s+I、 1s21に、アプライドオプティック
ス22巻19号の論文に示されているTiO2とSio
2膜の全部で23層の交互層からなる透過域波長130
0nmの帯域フィルタを用いた場合の1200μmの波
長の散乱光に対する減衰特性を、散乱光の光路に対する
角度を栴軸に、その時フィルタ(511,+521によ
って受ける散乱光の減衰量の計算値を縦軸にとって示し
たものである。図中破線はフィルタ(511又は(52
)単独による減衰特性実線は2枚のフィルタによる減衰
特性である。このフィルタは前述したように、フィルタ
への入射角15度即ち光路に沿う波長13QOnmの光
を透過し波長1200nmの光を減衰させるよう設計さ
れているので図に示す通し光路に沿う光線(角度0度)
に対しては各々のフィルタでそれぞれ30dB減衰され
、結局2枚のフィルタで60dBの減衰量が得られる。? Figure 1'S5 is a diagram to explain the situation during this time, and the filter (s+I, 1s21, TiO2 and Sio shown in the paper in Applied Optics Vol. 22, No.
Transmission range wavelength 130 consisting of 23 alternating layers in total of 2 films
The attenuation characteristics for scattered light with a wavelength of 1200 μm when a 0 nm bandpass filter is used. The angle with respect to the optical path of the scattered light is the axis, and the vertical axis is the calculated value of the amount of attenuation of the scattered light received by the filter (511, +521). The broken line in the figure indicates the filter (511 or (52).
) Attenuation characteristic by single filter The solid line is the attenuation characteristic by two filters. As mentioned above, this filter is designed to transmit light with a wavelength of 13Q Onm along the optical path at an incident angle of 15 degrees, and attenuate light with a wavelength of 1200 nm. Every time)
, each filter attenuates the signal by 30 dB, resulting in an attenuation of 60 dB with the two filters.
所が図より明らかなように、光路に対し一10度〜−2
0度の角でフィルタへ入射する波長1.2μmの光に対
してはほとんど減衰特性を示さない(図中矢印の部分)
。即ち従来の装置で用いられていたフィルタを多数枚重
ねて減衰量を得る手段はこのような光に対しては全(効
果がないことが9図より明らかである。一方前述したよ
うな原因で光回路内に生じる迷光は、一種の散乱光に近
いものであるから光路に対して一10度〜−20度の角
度範囲を含む広い角度成分を有する。このため従来のフ
ィルタ構成では、このような散乱光のうち特定の角度成
分を減衰させることができずクロストークの劣化を生じ
ていた。As is clear from the figure, the angle is 110 degrees to -2 degrees relative to the optical path.
There is almost no attenuation characteristic for light with a wavelength of 1.2 μm that enters the filter at an angle of 0 degrees (arrowed part in the figure).
. In other words, it is clear from Figure 9 that the means used in conventional devices to obtain attenuation by stacking many filters is completely ineffective against such light.On the other hand, due to the reasons mentioned above, Stray light generated in an optical circuit is close to a type of scattered light and has a wide angular component including an angular range of 110 degrees to -20 degrees with respect to the optical path.For this reason, conventional filter configurations It was not possible to attenuate specific angular components of the scattered light, resulting in crosstalk deterioration.
ここでは、特定の種類のフィルタを用いる場合について
の実例を示したが、実はこの現象は、干渉膜フィルタの
動作原理に基づく本質的なもので。Although we have shown an example in which a specific type of filter is used, this phenomenon is actually based on the operating principle of an interference film filter.
どのような干渉膜フィルタを用いても生じるものである
。即ち、干渉膜フィルタは、各層をなす膜の界面からの
反射光がその光路差に応じ互いに干渉しあうことによっ
てその透過・減衰波長特性を生じるものであるから、フ
ィルタへの入射角が変化するとこれに応じて光路差が変
化しその透過・減衰特性が変化する。例えばフィルタへ
の入射角αAで波長λAの光を透過させるフィルタは、
同じ光路差を生じる入射角αB波長λ8の光に対しても
透過特性を示す。α人、αB、λA、λB間の関係式は
(31式で与えられる。This occurs no matter what kind of interference film filter is used. In other words, in an interference film filter, the transmission and attenuation wavelength characteristics occur when the reflected light from the interface of the films forming each layer interferes with each other according to the optical path difference. Therefore, when the angle of incidence on the filter changes, Accordingly, the optical path difference changes and its transmission/attenuation characteristics change. For example, a filter that transmits light of wavelength λA at an angle of incidence αA is
It also exhibits transmission characteristics for light having an incident angle αB and wavelength λ8 that causes the same optical path difference. The relational expression between α person, αB, λA, and λB is given by (Equation 31).
λA = 130C1nm 、λB = f2(lon
m 、θイエ15°とすると、θB=27°となり、フ
ィルタが光路に対し15°傾むけられている場合は光路
に対しθい一θB即ち一12度で入射する波長1200
nmの光に対しても透過特性を示すこととなり、第5図
の特性を説明することができる。このように、波長多重
を行なう光回路においである特定の波長λAに対して入
射角 0人で透過特性となるフィルタを用いる場合、他
の波長λBに対しても必ず(3)式を満足するような入
射角 θBIこ対して当該フィルタは透過特性を示す。λA = 130C1 nm, λB = f2(lon
m, θ is 15°, then θB = 27°, and if the filter is tilted at 15° with respect to the optical path, the wavelength 1200 that is incident on the optical path at θ - θB, that is, 112 degrees.
It also exhibits transmission characteristics for nm light, which can explain the characteristics shown in FIG. 5. In this way, when using a filter that has transmission characteristics at an incident angle of 0 for a specific wavelength λA in an optical circuit that performs wavelength multiplexing, equation (3) must be satisfied for other wavelengths λB as well. For an incident angle θBI, the filter exhibits transmission characteristics.
従来の光回路では、光回路内での迷光については一切考
慮されていなかったため。This is because conventional optical circuits do not take any stray light into consideration within the optical circuit.
上述するような設計された光路と異なる角度でフィルタ
に入射する光源に対して配慮がなされておらずクロスト
ークの原因となった。特に、近年。No consideration was given to the light source entering the filter at an angle different from the designed optical path as described above, which caused crosstalk. Especially in recent years.
光回路の小形化に伴ない、第4図に示したように半導体
光素子を直接光回路内に組み込んだ回路への要求が高ま
っているが、このような光回路においては、光素子から
の出射光が一般にきわめて広い放射角を有することから
面述した光回路内で生じる迷光の強度が大きくなりこの
結果従来の光回路では罰述した原因によるクロストーク
が光回路の性能を大きく劣化させていた。With the miniaturization of optical circuits, there is an increasing demand for circuits in which semiconductor optical devices are directly incorporated into optical circuits, as shown in Figure 4. Since the emitted light generally has an extremely wide radiation angle, the intensity of stray light generated within the optical circuit described above increases, and as a result, in conventional optical circuits, crosstalk due to the causes described above greatly deteriorates the performance of the optical circuit. Ta.
勿論(31式から明らかなように、波長λAと波長λ8
の間隔を大きくとればこのような問題をかなりさけるこ
とができるが、情報密度の点からこのようt対策は望ま
しくないことは明らかである。Of course (as is clear from equation 31, the wavelength λA and the wavelength λ8
Although such a problem can be avoided to a large extent by increasing the interval between t and t, it is clear that such a countermeasure against t is not desirable from the viewpoint of information density.
この発明は、上記のような問題点を解消するためなされ
たもので従来の装置とほぼ同一の部品を用いながら、ク
ロストークの小さな光回路装置を得ることを目的とする
。The present invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain an optical circuit device with small crosstalk while using almost the same parts as conventional devices.
この発明に係る光回路装置では、所定の波長λAの光を
通過せしめ、他の波長λ8の光を減衰せしめる2枚のフ
ィルタを一組とし、この2枚のフィルタの法線が光路と
なす角は等しく、かつ光路に対し法線の方向が対称とな
るよう光路に挿入したものである。In the optical circuit device according to the present invention, a set includes two filters that allow light with a predetermined wavelength λA to pass through and attenuate light with another wavelength λ8, and an angle between the normal line of the two filters and the optical path. are inserted into the optical path so that they are equal and the directions of the normals to the optical path are symmetrical.
この発明に8ける光回路装置は、光路に対し異なる方向
に光路となす角が等しいように挿入された複数枚のフィ
ルタにより、減衰すべき波長λ3の光が光回路内で生じ
た何らかの原因によって迷光となって光路に対し零でな
い角度でフィルタへ入射しても、複数枚のフィルタへの
入射角が各々異なる為、そのうち少なくとも1枚のフィ
ルタで大きな減衰と必ず受はクロストークの劣化を生じ
ない。In the optical circuit device according to the eighth aspect of the present invention, a plurality of filters are inserted in different directions with respect to the optical path so that the angles with the optical path are equal, so that the light with the wavelength λ3 to be attenuated is Even if stray light enters a filter at a non-zero angle with respect to the optical path, the angle of incidence to each of the multiple filters is different, so at least one of the filters will inevitably experience large attenuation and crosstalk deterioration. do not have.
以下、この発明の実施例を図について説明する。 Embodiments of the present invention will be described below with reference to the drawings.
第1図はこの発明による光回路装置の一実苑例であって
(1)は波長12GOnmの光を出す半導体レーザ、(
2)は波長1300nmの光を受光するためのGe−A
PD、+31は光ファイバ、(4)は波長で200nm
の光を透過し、波長1300nmの光を反射させる干渉
膜フィルタ、 +61. +71. +81は光をコリ
メート又は集光させるためのレンズ、 +91(l[l
はプリズム、flllはミ5 +、 1st)、 15
21.1531. f5411:!各々前述シタTiO
2と5i02膜の交互層からなる23層のフィルタでこ
のフィルタへ入射角15度で入射する光線に対し波長1
300 nmの光に対し透過域で波長1200nmの光
に対し減衰域を示すものである。第2図はフィルタ+5
jl、 1521.1531. +541の光路への挿
入角度を示したものであって、フィルタ1511及び(
52jは第1図あるいは第2図で示したx −y −Z
軸座標示において、フィルタの法線がx −y平面内に
ありかつX軸(光路)と法線のなす角が−15度及び+
15度であるよう挿入されている。又フィルタ(53)
及び(54)は、フィルタの法線がx −z平面内にあ
りかつX軸(光路)に対し+15度及び−15変で挿入
されている。FIG. 1 shows an example of an optical circuit device according to the present invention, in which (1) is a semiconductor laser that emits light with a wavelength of 12 GO nm;
2) is Ge-A for receiving light with a wavelength of 1300 nm.
PD, +31 is optical fiber, (4) is wavelength 200nm
an interference film filter that transmits light with a wavelength of 1300 nm and reflects light with a wavelength of 1300 nm, +61. +71. +81 is a lens for collimating or condensing light, +91(l[l
is prism, full is Mi5+, 1st), 15
21.1531. f5411:! Each of the above-mentioned SitaTiO
This is a 23-layer filter consisting of alternating layers of 2 and 5i02 films.
It shows a transmission range for light with a wavelength of 300 nm and an attenuation range for light with a wavelength of 1200 nm. Figure 2 shows filter +5
jl, 1521.1531. It shows the insertion angle of +541 into the optical path, and shows the insertion angle of filter 1511 and (
52j is x −y −Z shown in Fig. 1 or 2
In the axis coordinates, the normal line of the filter is in the x-y plane, and the angle between the normal line and the X axis (optical path) is -15 degrees and +
It is inserted so that the angle is 15 degrees. Also filter (53)
and (54), the normal line of the filter is in the x-z plane and is inserted at +15 degrees and -15 angles with respect to the X axis (optical path).
次に第1図に従いこの発明の詳細な説明する。Next, the present invention will be explained in detail with reference to FIG.
半導体レーザ(1)より出射した波長f2(lonmの
光はレンズ(6)によって平行光束に変換され干渉フィ
ルタ(4)を透過しレンズ(7)によって集光されファ
イバ(3:へ送出される。一方ファイバ(31より入射
した波長1300nmの光は、レンズ(7)で平行光束
へ変換されたのち干渉フィルタ(4]で反射されプリズ
ムαG内を上方へ進みミラーαυで反射され光路(X軸
〕に沿って干渉フィルタ(511,(s21. +53
1. (541へ順次入射する。この光のフィルタへの
入射角はいずれも15度であるので、この波長の光はこ
れらのフィルタを透過しレンズ(8+によってGe−A
PD(21上へ集光される。また波長120[1nmの
光でファイバ伝送路中の接続点等により反射され上記波
長13QOnmの光と同一の光路を経て干渉フィルタt
5tl、 lzl、 (矧、 +541へ入射する成分
は、フィルタ(s+l、 (簡、 +531.1541
がこの光路(こ沿った入射角の光に対しては、波長13
00nmを透過せしめ波長1200nmを反射するもの
であるから4枚のフィルタによって強く減衰させられる
。これらの特性は、従来の光回路装置と全く同様である
。Light with a wavelength f2 (lonm) emitted from the semiconductor laser (1) is converted into a parallel beam by a lens (6), passes through an interference filter (4), is focused by a lens (7), and is sent to a fiber (3). On the other hand, light with a wavelength of 1300 nm that enters the fiber (31) is converted into a parallel beam by the lens (7), reflected by the interference filter (4), travels upward in the prism αG, is reflected by the mirror αυ, and goes along the optical path (X axis). along the interference filter (511, (s21. +53
1. (Sequentially incident on 541. Since the angle of incidence of this light on the filters is 15 degrees, the light of this wavelength passes through these filters and enters the lens (Ge-A
The light is focused onto the PD (21). Also, the light with a wavelength of 120 [1 nm is reflected by a connection point in the fiber transmission line, and passes through the same optical path as the light with a wavelength of 13 QOnm, and then passes through the interference filter t.
The component incident on 5tl, lzl, (矧, +541 is the filter (s+l, (simplified, +531.1541
is this optical path (for light with an incident angle along this path, the wavelength is 13
Since it transmits wavelengths of 1,200 nm and reflects wavelengths of 1,200 nm, it is strongly attenuated by the four filters. These characteristics are exactly the same as those of conventional optical circuit devices.
つぎに、従来の光回路装置でクロストークの原因となっ
た半導体レーザ(1)より出射した波長1200nmの
光がプリズムrLlのエツジ等の何らかの原因で散乱さ
れこの光回路装置内で迷光となってフィルタ(511へ
光軸に対し巾広い角度で入射する成分について考える。Next, the light with a wavelength of 1200 nm emitted from the semiconductor laser (1), which caused crosstalk in the conventional optical circuit device, is scattered by some reason such as the edge of the prism rLl and becomes stray light within this optical circuit device. Consider components that enter the filter (511) at wide angles with respect to the optical axis.
簡単のためまずこのような光線が第2図+a+に示すよ
うにx −y平面内で光軸に対しθinの角度で入射す
る場合について述べる。この光はフィルタ(51)に対
してθin+15 の角度で入射しさらにフィルタ(5
21へθ1n−15の角度で入射する。For the sake of simplicity, we will first describe the case where such a light ray is incident on the x-y plane at an angle θin with respect to the optical axis, as shown in FIG. 2+a+. This light enters the filter (51) at an angle of θin+15, and then filters (51) at an angle of θin+15.
21 at an angle of θ1n-15.
この結果この2枚のフィルタ(51)及び(52)によ
って異なる減衰をうける。第3図は波長1200nmの
迷光がフィルタ(511及び(521を通過するときに
うける減衰特性の計算値を迷光の光路(ZWIJ) l
ζ対する角度を横軸に、減衰量を縦軸にとって示したも
ので図中2本の破線は、フィルタ(511及び(52)
の各々によって受ける減衰特性を、実線はフィルタ(5
1)及びl52)の両方によってうける減衰特性を示し
ている。As a result, the two filters (51) and (52) receive different attenuation. Figure 3 shows the calculated values of the attenuation characteristics that stray light with a wavelength of 1200 nm undergoes when it passes through filters (511 and (521).
The horizontal axis represents the angle to
The solid line represents the attenuation characteristics experienced by each of the filters (5
1) and l52) are shown.
例えば光軸に対して+15度の角でフィルタ(511へ
入射する迷光は、第3図に示すようにフィルタ(51)
では全く減衰されない、これは、(31式の関係をこの
光線が満足しているからで、従来の光回路装置のクロス
トーク劣化の原因となっていた現象である。しかしなが
らこの発明による光回路装置ではとの迷光は、第3図に
示すように2次のフィルタ(521によって30dB近
くの強い減衰をうけ除去される。第3図より明らかなよ
うに光路に対し+30度近くの迷光までがこのようなフ
ィルタ構成によって強く減衰される。このことを従来の
光回路装置においては、光路に対し一5°〜35度の範
囲でしか迷光を除去できなかった(第5図)ことと比較
するとこの発明による効果がきわめて大きいことがわか
る。所で、今までは、迷光がx −y面内で光路に対し
て広い角度をもって入射することを考えたが一般にはt
”−y面内に8いても同様の迷光が考えられる。このよ
うな迷光に対してはフィルタ(53)及び(54)が同
様の効果を示すことは、上述した動作原理より明らかで
あろう。For example, the stray light incident on the filter (511) at an angle of +15 degrees to the optical axis is
This is because this light ray satisfies the relationship of Equation 31, which is a phenomenon that causes crosstalk deterioration in conventional optical circuit devices. However, the optical circuit device according to the present invention As shown in Figure 3, the stray light is strongly attenuated by nearly 30 dB and removed by the second-order filter (521). This is strongly attenuated by a filter configuration like this.Compare this with the fact that in conventional optical circuit devices, stray light could only be removed within the range of 15° to 35° relative to the optical path (Figure 5). It can be seen that the effect of the invention is extremely large.By the way, until now we have considered that stray light is incident at a wide angle with respect to the optical path in the x-y plane, but in general, t
Similar stray light can be considered even if there are 8 in the -y plane.It is clear from the operating principle described above that filters (53) and (54) have the same effect on such stray light. .
さらに、上述した動作原理より明らかなように。Furthermore, as is clear from the operating principle described above.
フィルタ+511. (521の光路への挿入角は、減
衰せしめる波長の光が1つのフィルタに対して透過とな
る入射角に対してもう1つのフィルタが最大の減衰量を
与えることによって最大の効果が得られることは明らか
である。Filter +511. (The insertion angle of 521 into the optical path is such that the maximum effect can be obtained by having the other filter give the maximum amount of attenuation for the incident angle at which the light of the wavelength to be attenuated is transmitted to one filter. is clear.
ここ、で、フィルタの法線と光路とのなす角をαとし、
透過すべき波長をλB減衰すべき波長をλ8とすると、
このフィルタが波長λBに対し透過域となるフィルタへ
の入射角θBは(3)式より次のように与えられる。Here, let the angle between the normal of the filter and the optical path be α,
If the wavelength to be transmitted is λB and the wavelength to be attenuated is λ8, then
The incident angle θB to the filter at which the filter has a transmission range for the wavelength λB is given by equation (3) as follows.
1枚のフィルタを(4)式で与えられる角度 θ8で透
過してきた波長λBの光がこれと1対をなすもう1枚の
フィルタへ入射する角θmは、2つのフイルタが2αの
角をなしていることから次式で与えられる。The angle θm at which the light of wavelength λB that has passed through one filter at the angle θ8 given by equation (4) is incident on the other paired filter is the angle θm where the two filters form an angle of 2α. Therefore, it is given by the following equation.
θ −2α−θB(5)
従ってフィルタが(5)式で与えられる入射角の波長λ
8に光に対して最大の減衰量を与えるようにすればこの
発明の効果を最大限発揮できる6訂述した実権例はこの
ように条件に合致するようフィルタの挿入角を設定した
ものである。θ −2α−θB (5) Therefore, the wavelength λ of the filter at the angle of incidence given by equation (5)
The effect of this invention can be maximized by giving the maximum amount of attenuation to light in 8. In the actual example described in 6, the insertion angle of the filter is set so as to meet the conditions as described above. .
一般には、フィルタの最大減衰域はフィルタの膜構成に
よって異なるため個々のフィルタについてそれぞれ設計
することが必要である。Generally, the maximum attenuation range of a filter differs depending on the membrane configuration of the filter, so it is necessary to design each filter individually.
さて、上述したように、この発明は、従来の光回路装置
とほとんど同一の部品で構成できるにもかかわらず、わ
ずかにフィルタの光軸への挿入方向に工夫をこらすこと
によって従来の光回路装置の欠点を著しく改善できる。Now, as mentioned above, although the present invention can be constructed from almost the same parts as the conventional optical circuit device, it is possible to make the conventional optical circuit device can significantly improve the shortcomings of
即ち、従来の光回路装置と同等の部品でかつほとんど同
一の組立方法でしかもすぐれた効果が得られる特長を有
するものである。In other words, it has the advantage of being able to use the same components as conventional optical circuit devices and using almost the same assembly method, and yet provides superior effects.
fX2+に、記実施例では、フィルタを4枚挿入する場
合について示したがさらに大きな減衰量を得るには各々
のフィルタをさらに複数枚としても良い。又光回路装置
は、第1図に示すように一般に光路に対し軸対称ではな
いので、迷光も光路に対し軸対称な角度成分をもつとは
かぎらない。例えば第1図において、迷光がx −7面
内でのみ光路に対し広い角度を有する場合フィルタ+5
31. (541は除いても同じ効果を得ることができ
る。また上記実権例では、半導体光素子が光回路装置中
に組み込まれている場合について述べたが半導体光素子
の代りに光ファイバを置いても良い、また実症例では同
一のフィルタを用いる場合について示したが各々に異な
るフィルタを用いても+11式がフィルタ一般に成立す
ることから明らかなように、同様の効果を期待できる。In the above embodiment, four filters are inserted into fX2+, but in order to obtain an even larger amount of attenuation, each filter may be provided with a plurality of filters. Furthermore, since optical circuit devices are generally not axially symmetrical with respect to the optical path as shown in FIG. 1, stray light does not necessarily have an angular component that is axially symmetrical with respect to the optical path. For example, in Figure 1, if the stray light has a wide angle to the optical path only in the x-7 plane, the filter +5
31. (The same effect can be obtained even if 541 is omitted.Also, in the above practical example, the case where a semiconductor optical device is incorporated in an optical circuit device is described, but an optical fiber may be placed in place of the semiconductor optical device. Although the case where the same filter is used in the actual case has been shown, the same effect can be expected even if different filters are used, as is clear from the fact that the formula +11 holds true for filters in general.
しかしながら、同一のフィルタを用いてすぐれた効果を
有することもこの発明の利点の1つであり、この方が量
産性及び製造性に優れていることはいうまでもない。However, one of the advantages of the present invention is that it can produce excellent effects using the same filter, and it goes without saying that this method is superior in mass production and manufacturability.
以上のように、この発明によれば、フィルタを光路に対
し同−角で異なる方向にむけて縦列挿入したので、従来
の光回路装置と同等の部品及び製造法でしかもきわめて
クロストークの小さなものが得られる効果がある。As described above, according to the present invention, since the filters are inserted in tandem at the same angle to the optical path but facing different directions, it is possible to use the same components and manufacturing methods as conventional optical circuit devices, and to achieve extremely low crosstalk. There is an effect that can be obtained.
第1図はこの発明による光回路装置の一実池例の上面図
、第2図1allblはこの発明による光回路装置のフ
ィルタの光路への挿入角度を説明する断面図、第3図は
この発明による効果を計算した特性図、第4図は従来の
光回路装置の一例を示す上面図、第5図は従来の光回路
装置のクロストークの原因を説明する特性図である。
(1)は波長1200nmの半導体レーザ、(2)はG
e−APD、+31はファイバ、(4)はフィルタ、
+61゜+71. +81はレンズ、 +91. Qf
lはプリズム、α0はミラー。
(51,(sz、 f531+ (54は干渉膜フィル
タである。なお。
図中、同一符号は同−又は相当部分を示す。FIG. 1 is a top view of an example of an optical circuit device according to the present invention, FIG. 2 is a sectional view illustrating the insertion angle of the filter of the optical circuit device according to the present invention into the optical path, and FIG. 3 is a cross-sectional view of the optical circuit device according to the present invention. FIG. 4 is a top view showing an example of a conventional optical circuit device, and FIG. 5 is a characteristic diagram illustrating the cause of crosstalk in the conventional optical circuit device. (1) is a semiconductor laser with a wavelength of 1200 nm, (2) is a G
e-APD, +31 is fiber, (4) is filter,
+61°+71. +81 is the lens, +91. Qf
l is a prism and α0 is a mirror. (51, (sz, f531+) (54 is an interference film filter. Note that in the drawings, the same reference numerals indicate the same - or corresponding parts.
Claims (1)
を反射または減衰せしめる目的で複数枚の干渉膜フィル
タが光路中に挿入されている光回路装置において、上記
干渉膜フィルタのうち少なくとも1対の干渉膜フィルタ
が、その法線が光路に対し零でない角度αをもつて挿入
されており上記1対の干渉膜フィルタが互いに角度2α
をなしていることを特徴とする光回路装置。 2、所定の波長λ_Aの光を透過せしめ、他の波長の光
を反射または減衰せしめる目的で複数枚の干渉膜フィル
タが光路中に挿入されている光回路装置において、上記
干渉膜フィルタのうち少なくとも1対の干渉膜フィルタ
やその法線が光路に対して零でない角度αをもつて挿入
されており、またこの1対の干渉膜フィルタが互いに角
度2αをなし、かつ他の1対の干渉膜フィルタが上記1
対の干渉膜フィルタを光路を中心軸として90度回転さ
せた傾きで挿入されていることを特徴とする光回路装置
。 3、所定の波長λ_Aの光を透過せしめ、他の波長λ_
Bの光を反射または減衰させる目的で複数枚の干渉膜フ
ィルタが光路中に挿入されている光回路装置において、
干渉膜フィルタの法線と光路とのなす角をα、上記干渉
膜フィルタが波長λ_Bの光に対して最大の減衰量を与
える波長λ_Bの光の干渉膜フイルタへの入射角をθ_
mとすると、θ_mとαとの間に(1)式の関係が成立
することを特徴とする特許請求の範囲第1項又は第2項
記載の光回路装置。 θ_m=2_α−θ_B(1) ここでθ_B=cos^−^1{(λ_B/λ_A)c
osα}(2)である。[Claims] 1. In an optical circuit device in which a plurality of interference film filters are inserted in an optical path for the purpose of transmitting light of a predetermined wavelength λ_A and reflecting or attenuating light of other wavelengths, the above-mentioned At least one pair of the interference film filters is inserted with its normal at a non-zero angle α with respect to the optical path, and the pair of interference film filters are at an angle of 2α to each other.
An optical circuit device characterized by comprising: 2. In an optical circuit device in which a plurality of interference film filters are inserted in an optical path for the purpose of transmitting light of a predetermined wavelength λ_A and reflecting or attenuating light of other wavelengths, at least A pair of interference film filters and their normals are inserted at a non-zero angle α with respect to the optical path, and the pair of interference film filters form an angle 2α with each other, and the interference film filters of the other pair make an angle 2α with respect to the optical path. The filter is 1 above
An optical circuit device characterized in that a pair of interference film filters are inserted at an angle rotated by 90 degrees about an optical path as a central axis. 3. Allows light of a predetermined wavelength λ_A to pass through, and transmits light of other wavelengths λ_
In an optical circuit device in which a plurality of interference film filters are inserted in the optical path for the purpose of reflecting or attenuating the B light,
Let α be the angle between the normal line of the interference film filter and the optical path, and let θ_ be the angle of incidence of the light of wavelength λ_B on the interference film filter at which the interference film filter gives the maximum amount of attenuation for the light of wavelength λ_B.
The optical circuit device according to claim 1 or 2, wherein the relationship of equation (1) is established between θ_m and α, where m is the value of θ_m. θ_m=2_α−θ_B(1) where θ_B=cos^−^1{(λ_B/λ_A)c
osα} (2).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16915786A JPS6325604A (en) | 1986-07-18 | 1986-07-18 | Optical circuit device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16915786A JPS6325604A (en) | 1986-07-18 | 1986-07-18 | Optical circuit device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6325604A true JPS6325604A (en) | 1988-02-03 |
Family
ID=15881339
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP16915786A Pending JPS6325604A (en) | 1986-07-18 | 1986-07-18 | Optical circuit device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6325604A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0444694A2 (en) * | 1990-03-02 | 1991-09-04 | Fujitsu Limited | Optical coupler |
JPH0626931A (en) * | 1992-03-26 | 1994-02-04 | Alcatel Cit | Optical filter including fabry-perot type interferometer tunable by rotation |
-
1986
- 1986-07-18 JP JP16915786A patent/JPS6325604A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0444694A2 (en) * | 1990-03-02 | 1991-09-04 | Fujitsu Limited | Optical coupler |
JPH0626931A (en) * | 1992-03-26 | 1994-02-04 | Alcatel Cit | Optical filter including fabry-perot type interferometer tunable by rotation |
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