JP2993516B2 - Optical connection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connection device for simultaneously distributing and transmitting optical information from one optical input device to a plurality of optical output devices.

[Conventional technology]

In such a field, as shown in FIG. 10, an optical element for simultaneously transmitting information between two-dimensional images in parallel is required. Information S ₁ than one input surface I _s, S ₂ ... multiple output plane _{S n O s1, O s2,} ... O in order to transfer the _sn conventional as shown in FIG. 11, the polygonal mirror 3 There is a method of mechanically scanning.

That is, the signal light S ₁ , S ₂ is transmitted (connected) to the output surfaces (light receiving surfaces) O _s1 , O _s2 by rotating the deflecting mirror 3 around the rotation axis 5 to the 3 ′ position.

[Problems to be Solved by the Invention] However, in such an optical system, the scanning (deflection) of light depends on the rotation of the deflecting mirror 3, so that the signal light
There is a fatal problem that S ₁ and S ₂ cannot be simultaneously transmitted to the respective output surfaces O _s1 and O _s2 . The deflection mirror 3
In addition, a high-precision positioning mechanism is required for the rotation of the mirror, and the switching of the deflecting mirror takes much time compared to the generally required information speed, so that it is not suitable for high-speed information transmission.

An object of the present invention is to realize an optical connection device having a simple structure capable of distributing and transmitting optical information to a large number of optical output devices substantially simultaneously without using an element having a mechanically movable portion such as a deflection mirror.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, an optical input device including a light emitting device having a plurality of wavelengths, and reflects only predetermined wavelengths from these optical input devices and transmits light of other wavelengths There is provided an optical connection device having a plurality of reflective filters having wavelength selectivity and an optical output element having a plurality of light receiving elements for receiving respective wavelengths transmitted through the reflective filters.

The light input element is constituted by a pixel constituted by a plurality of light emitting elements having a plurality of wavelengths or a pixel constituted by a light emitting element having a variable wavelength.

(Operation)

FIG. 1 shows the principle and operation of this method. Input signal surface I _s is a display for displaying a two-dimensional image, the output plane O _s1, O _s2
Is a two-dimensional array of photodetectors such as photodiodes. Maximum plurality of output surfaces O _s1, O _s2, ... deflection element for distributing signals to O _sn, as shown in Figure 2, different wavelengths lambda _1, respectively, lambda _2, reflectivity for ... lambda _n is , reflective filters F ₁ of two or more having wavelength selectivity such that F _2, is formed by ... F _n.

According to the filter having such wavelength selectivity, the output surface O _s1 by the wavelength of the light source, O _s2, ... at the same time signal any or all of the O _sn output S _1, S _2, it can be selected ... S _n (FIG. 3).

As the reflection type filter having the wavelength selectivity, for example, a volume phase hologram or a dielectric multilayer film is used.

〔Example〕

The input surface is composed of N × N pixels 20. Each pixel 20
There is a light emitting element whose oscillation wavelength is variable. An element having such a function can be realized by using, for example, a mode hop of a semiconductor laser. Changing the wavelength
This is achieved, for example, by changing the ambient temperature or the current. That is, for example, as shown in FIGS. 4A and 4B, when a semiconductor laser 31 is used as a light source, the wavelength of the semiconductor laser changes depending on the temperature (FIG. 4B). By adjusting the heating temperature of the semiconductor laser 31, the oscillation wavelength can be changed. In addition, 35 is a heat sink, 36 is a heat conductive support connecting the semiconductor laser 31 and the Peltier element, and 37 is a substrate. Or, separately, an external cavity
40 (FIG. 6), and by changing the resonator length l as is well known, the wavelength .lambda. Can also be changed.

These pixels 20 represent a two-dimensional image of a binary logical value or an element of a logical value matrix. The input signal makes the light intensity correspond to a logical value, for example. Reflective filters F ₁ to couple the input and output surfaces, F _2, ... F _n is, any wavelength lambda ₁ of the light source of the input surface I _s, lambda _2, high reflection diffraction efficiency for ... lambda _n ( (FIG. 2), which has selectivity for transmitting light having a wavelength other than the specific wavelength. Input surface I _s arbitrary pixel 20 and two or more output face on _{O s1, O s2, ... O} sn signaling between (optical connection) is required, and corresponding to the display (lighting) to the pixel If the logic value is input, the corresponding light emitting elements of the input surface I _s to emit light.

Apart from the above, as shown in FIG. 7, each pixel 20 emits a plurality of light beams having different wavelengths.
₁ , λ ₂ , λ ₃ , λ ₄ may be provided.

For example, as the first 8-9 Figure, the pixels of the input plane I _s 20-1,20
It is assumed that a signal is transmitted between the output surfaces O _s1 and O _s3 among the two output surfaces. Each pixel 20 has a light emitting element that emits at least four different wavelengths of light corresponding to the number of output surfaces. Here, the connection with the output surfaces O _s1 and O _s3 is made,
Since the connection with the output surfaces O _s2 and O _s4 is not made, a true logical value 1 is applied to the light emitting device corresponding to the output surfaces O _s1 and O _s3 and the light emitting device corresponding to the output surfaces O _s2 and O _s4. Enter a false logical value 0. The logical product of this logical value and the input signal to the light emitting element is calculated, and the one that takes a true value emits light. The pixels 20-1 and 20-2 make the same optical connection, but do not emit light because the input signal of the pixel 20-2 is 0, and only the elements corresponding to the output surfaces O _s1 and O _s3 in the pixel 20-1 Emits light.

According to this method, since the optical connection is selected according to the wavelength of the light emitting element, signal transmission in real time is possible, and
Different optical connection paths can be selected for each pixel.

Incidentally, the logical product can also be performed by disposing an optical shutter between the input surface and the reflection type filter.

〔The invention's effect〕

As described above, according to the present invention, a deflecting mirror is not required, and mechanical accuracy is reduced.

Also, optical information can be distributed and transmitted to a plurality of output elements at the same time.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the basic principle of the present invention, FIG. 2 is a diagram illustrating the reflectance characteristics of a wavelength selection filter, FIG. 3 is a diagram illustrating the operation of the present invention, FIG. 4A and FIG. Is a schematic diagram showing a wavelength control structure of a semiconductor laser and a diagram showing a wavelength change due to a temperature change thereof, FIGS. 5 and 6 are a schematic diagram showing an external resonator and a wavelength characteristic diagram thereof, and FIGS. 9 is an illustrative view for explaining an example of an optical connection path, FIG. 10 is an illustrative view showing a conventional optical distribution and transmission method, and FIG. 11 is an illustrative view showing a conventional deflection method. 20 ...... pixels, I _s ...... input surface, F ...... reflective filters, O _s ...... output surface.

────────────────────────────────────────────────── (5) References JP-A-62-184404 (JP, A) JP-A-60-103835 (JP, A) JP-A-52-90957 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) G02B 27/10 H04B 10/02

Claims (2)

(57) [Claims] An optical input device (20) having a pixel composed of a plurality of light emitting devices having a plurality of wavelengths, and a light of a predetermined wavelength reflected from the optical input device and a light of another wavelength. Is an optical connection having a plurality of wavelength-selective reflective filters (F) that transmit light, and an optical output element (O _s ) having a plurality of light receiving elements that receive respective wavelengths transmitted through the reflective filters. apparatus. 2. An optical input element (20) composed of pixels composed of light emitting elements having variable wavelengths, and reflects light of a predetermined wavelength from the optical input element and transmits light of other wavelengths. Reflective filters with wavelength selectivity (F)
And an optical output device (O _s ) having a plurality of light receiving elements for receiving respective wavelengths transmitted through the reflection type filter.