JPS58203413A - By-pass type optical repeater - Google Patents

Abstract

PURPOSE:To integrate effectively an optical by-pass circuit and make it small in size and inexpensive, by forming input and output ports for a multiple mode fiber and input and output ports for a light emitting element and a photodetector. CONSTITUTION:Two Fresnel zone plates F1 and F2 whose center positions are close to each other are formed on the rear face of a light-transmissive substrate S. These Fresnel zone plates F1 and F2 have the same optical characteristics to constitute a two-focus reflective focusing optical system. On the front face of the substrate S, first optical input/output ports M11, M22, M21, and M12 for up and down lines are positioned optically by Fresnel zone plates F1 and F2 and are provided, and second optical input/output ports R1, T1, R2, and T2 for a repeating circuit are provided as ports for up and down lines. The multi- mode optical signal is supported effectively by the two-focus reflective focusing optical system constituted of two Fresnel zone plates F1 and F2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a highly practical arm-to-arm optical repeater used in a multimode optical network.

[Technical background of the invention and its problems]

With the development of optical communication technology, various optical networks have been developed. Among these, optical repeater networks are attracting attention for their practical application because they are highly expandable and easy to handle. However, if a failure occurs in this type of optical repeater, this will hinder optical communication throughout the network, so various countermeasures have been taken. One possibility is to duplicate the network, but this is extremely disadvantageous in terms of network installation costs and other aspects. A vessel/? Attempts are being made to avoid this.

However, when realizing an optical repeater with such a bypass function, miniaturization and cost reduction remain issues.

However, in recent years, so-called optoelectronic integrated circuit technology has attracted attention as a means to solve the above problems. However, the pi-plane optical repeaters made of optoelectronic integrated circuits, which have been studied in various ways, are those that simply form an optical repeater on a semiconductor substrate, or those that are optical repeaters that are compatible with single mode fibers. This is simply an optical repeater that includes a branch circuit formed on a semiconductor substrate, and has not been put into practical use to be compatible with optical networks using multimode fibers, which are expected to increase in the future. In other words, there is a strong desire to put into practical use a pinomace type optical repeater that is compact and can be mass-produced at low cost and is compatible with multi-mode fibers that effectively utilizes optoelectronic integrated circuit technology.

[Purpose of the invention]

The present invention was made in consideration of the car situation as described above.
The aim is to be able to effectively integrate optical/innovative circuits that match multimode fibers.
Moreover, it is an object of the present invention to provide a highly practical bypass type optical repeater that can be made smaller and lower in cost.

[Summary of the invention]

The outline of the present invention is to form a bifocal reflection type focusing optical system as a directional coupler for a semiconductor crystal plate or a dielectric, and to form a multi-mode reflection type focusing optical system on the surface of the transparent substrate in association with the reflection type Kato optical system. input ports and output ports of the phi.
Input ports and output ports for a light emitting element and a light receiving element for the optical 794791 circuit are respectively formed.

〔Effect of the invention〕

Therefore, according to the present invention, it is possible to bypass and relay the optical signal while ensuring sufficient isolation of the optical signal communicated in multiplex mode, and also to ensure sufficient electrical isolation of the optical bypass circuit. can be secured. Further, it can be easily miniaturized and the cost can be reduced due to single production, which is extremely effective in practical use.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the spectral state of optical signals bidirectionally communicated in a bypass type optical repeater.

The two-way communication of the optical signals mentioned above can be achieved by, for example, using a two-core optical fiber cable as an optical network line, and one side of the cable is an upstream line,
This is done using the other side as the down line. In the repeater, the optical signal on the up line is transmitted from the input port M11 to the output port M1. ni・nii A? The optical signal of the down line is input to port M! 1 to output port M1. The mother of the mother is taken care of. Further, the optical signal on the upstream line input to the input port M11 is branched to the output port R1, and after passing through an optical repeater circuit, it is sent from the input port T1 to the output port M! ! The result is synthesized and output. Similarly, the optical signals on the downlink line are branched from the manual port M,1 to the output port R7, and after passing through the optical repeater circuit, are combined and output from the input port T to the output port M, .

In this way, the input port and the output port are directionally coupled for each upstream and downstream line. Nonoi'? which has such a demultiplexing function? The optical signal on the uplink line and the optical signal on the downlink line are each relayed or passed through a "S-type" optical repeater.

The pino-four type optical repeater according to the embodiment of the present invention combines a bidirectional directional coupler as shown in FIG. 1 and an optical repeater circuit into one.
It is constructed by simultaneously integrating two optical elements, and is schematically constructed as shown in FIG. 2, for example.

In Fig. 2, the light-transmitting substrate S is made of, for example, a [-■ group compound semiconductor crystal plate, or a dielectric crystal plate such as sapphire, etc., and on the back side there are two Fresnel zone plates whose centers are close to each other. F, ,F, is formed. These Fresnel zone plates F□ and Ft have the same optical characteristics and are arranged symmetrically in a so-called semicircle, thereby forming a bifocal reflective focusing optical system.

On the surface of the substrate S, optical positioning is performed by the Fresnel zone relays F, , F, and the first optical input/output ports M1 .
．． M=,M,, 0M,.

are provided respectively, and second optical input/output ports R1+TI I R1@Tt for the relay circuit are provided separately for the up line and the down line. That is,
A first optical input port M11 and a first optical output port M! for the uplink line. ! is also the first optical input yN- for the down line
M, 1 and the first previously mentioned capo Ml, have a plane of symmetry with a plane Σ on the surface of the substrate S that includes the central axis of the Fresnel zone plates F, , p, and the Fresnel zone plates They are symmetrically provided on a plane A that is perpendicular to the plane of symmetry that passes through the central axis of F and is perpendicular to the plane of symmetry. In this case, input/output ports M, , M1 . is the input/output capo for the upstream line) Ml.

M2. Compared to the above, it is provided at a position close to the symmetry plane Σ and spatially separated from the upstream line input/output capos (M, . . . , M), that is, optically isolated.

As a result, these input and output capos are shown in Figure 3.
',M,! ,M,1. As shown in the relationship between M1ffi and Fresnel zone plate F1, optical input port M, 8
The optical signal on the uplink line inputted from
) is focused and guided by MttJ. Further, the optical signal for the down line inputted from the optical input port M21 is the optical input yl? -) M, , is an optical output port M1 located at a symmetrical position with respect to the first plane of symmetry Σ! It will be focused and guided by. At this time, the above input/output date M, , M□
, M! , , Ml, the optical signal on the up line and the optical signal on the down line are not mixed.

On the other hand, on the surface of the substrate S, a first optical input port M, 1 for the uplink line is arranged symmetrically with respect to the center axis of the Fresnel zone plate F, and a second optical output port for the uplink line relay is arranged symmetrically to the center axis of the Fresnel zone plate F. A port R1 is provided, and a first optical output port M! !
A second optical input port T is provided symmetrically to. Also, the first optical input port M1 for the down line. A second optical output port R1 for relaying is provided symmetrically with respect to the first optical output port M1ffi, and a second optical input port T for relaying is provided symmetrically with respect to the first optical output port M1ffi. These second optical input/output ports R□, T1°R,,T, are the optical input/output ports M1. .

M! ,,M□9M1. On the other hand, as shown in FIG. 4, they are optically symmetrical with respect to the Fresnel zone plate F2. As a result, these optical input/output ports are optically coupled with directionality, as shown in the above-mentioned Figure @1.

Therefore, the second capo R, , on the surface of the substrate S is
A semiconductor light-receiving element is formed above R, and a semiconductor light-receiving element as a light source is integrated above the optical input port T, , T of @2. Each of these semiconductor light-emitting/light-receiving elements is attached to a specified substrate S.
Transmission electronic circuit TC similarly integrated on the surface of
,,TC, and receiving electronic circuit Rc.

RC, respectively, and are each driven.

Note that these semiconductor elements and semiconductor circuits may be formed in an integrated manner using this as a base when the substrate 1 is a semiconductor crystal plate, and when the substrate 1 is a dielectric crystal plate such as sapphire. Alternatively, the semiconductor element may be formed in an integrated manner as a so-called SO8 structure. Furthermore, if the semiconductor element is formed using amorphous semiconductor technology, it is possible to appropriately use a substrate material having light-transmitting properties without requiring crystallinity for the substrate S. becomes.

As described above, according to the bypass type optical repeater according to the present invention, two Fresnel zone plays) Fl.

The 2s point reflection type Someto optical system formed by F makes it possible to effectively support multimodal optical signals. In addition, each optical input/output port can be optically isolated and connected with directionality.
It is possible to effectively interconnect optical fibers that can be integrated. In addition, as described in q above, the components can be effectively integrated on one substrate S, and miniaturization and cost reduction can be effectively achieved. Furthermore, the interconnection with the optical fiber described above can be easily and reliably performed with relaxed assembly accuracy.

Furthermore, since the signal levels handled by the transmitting section and receiving section that make up the relay circuit are significantly different, it is generally necessary to place them spatially apart to avoid problems of interference between them. . On the other hand, according to the repeater according to the present invention, it is possible to easily and effectively meet the requirements, and the repeater has effects such as extremely high practicality.

Therefore, it is possible to provide a bypass type optical repeater which has a simple configuration and has great practical advantages without causing the conventional problems. Further, as a bifocal focusing optical system, thermal diffusion is performed on the substrate to form a high refractive portion H through two diffusion apertures located close to each other as shown in FIG.
Does forming a reflective film r cause snoring after removing the diffusion aperture mask? It is possible to use an axial lens system.

Note that the present invention is not limited to the above embodiments. For example, the composition of the substrate S and its optical properties may be determined according to required specifications. Furthermore, although a bidirectional communication type has been described here, a unidirectional communication type can be similarly implemented. Furthermore, it is possible to integrate relay functions of three or more systems at the same time, and the point is that if sufficient optical and electrical isolation is ensured between the input and output ports, it will be possible to It is possible to transform and implement.

[Brief explanation of drawings]

The figure shows one embodiment of Honkakumei. Figure 1 shows the distribution state of optical signals in the repeater and directional coupling between optical input and output ports. Figure 2 shows the outline and configuration of the repeater. Figures 1, 3 and 4 show the optical positional relationship between the presnel zone plate and the optical input/output port. FIG. 5 is a main part configuration diagram showing another embodiment of the present invention. , M, , , , . . . 1st optical input port for up line, Mt2 . . . 1st optical output port for up line, R
8... Optical output port of uplink line 1 and 2, T1...
Optical input port of fjjJ2 for up line, M, 1...first optical input port for down line, M,2...'first optical output port for down line, R1...first optical output port for down line 2 optical output port, T, ... for down line '@2 optical input port, S... translucent substrate, "IsF!... Fresnel zone plate, Σ... plane of symmetry, RC, ,RC,...
Semiconductor transmitting circuit, TC,, TC,... Semiconductor transmitting circuit, r... Reflective film, H... High 1... Folded part. Applicant's agent Patent attorney Suzue Takeshi Hikogure 1 Figure 2 Figure 3v! J Figure 4 73-

Claims (1)

[Scope of Claims] ttl A bifocal reflection type focusing optical system whose center position is close to the back surface of the translucent substrate, and a bifocal reflection type focusing optical system disposed on the surface of the translucent substrate. A first optical input port and a first optical output port are symmetrically provided at a plane position perpendicular to the plane of symmetry passing through the central axis of one of the reflective focusing optical systems with a plane containing each central axis as the plane of symmetry. and a second optical output port provided on the surface of the translucent base symmetrically to the first optical input port with the center axis of the other reflective focusing optical system as the line of symmetry, and the first optical output port. 1. A bypass type optical repeater, comprising: an optical output port and a second optical input port provided symmetrically to the optical output port. (2) The light-transmitting substrate is made of a semiconductor crystal plate or a dielectric crystal plate, and optical semiconductor elements are integrated and formed on the surface of the substrate. S-type optical repeater. (3) The bifocal reflective focusing optical system is composed of two adjacent Fresnel zones.
Arm type optical repeater. (4) A semiconductor light emitting element and a semiconducting light receiving element are multiplied and formed at the optical input port and first optical output column port position of il, or at the second optical input port and second optical output port position. A bypass type optical repeater according to claim 1. (5) The bifocal reflection type focusing optical system comprises a reflection type lens formed with thermal diffusion ↑ and having a reflection film applied to the back surface of the 9-i matrix type optical repeater according to claim 1.