JPS62192709A - Light transmitting equipment - Google Patents

Abstract

PURPOSE:To make it possible to separate and detect many light beams having wavelength of very close wavelength interval at high resolution using simple constitution by installing a light pulse signal receiving equipment and providing a wavelength selecting filter made of a specified medium in the device. CONSTITUTION:The titled device is provided with a light pulse signal receiving equipment 41 providing a wavelength selecting filter 4a made of a medium that reduces light absorption factor sharply and selectively for each wavelength of plural light beams 10, 11 of different wavelength by photochemical hole burning. Plural light beams 10, 11 are transmitted to a distributor 2 by a light pulse signal transmitting equipment 41 and distributed almost equally to each lens array of a fiber lens array 3 and made to incident on each light detector 5a of a light detector array 5 through a wavelength selecting filter array 4. Thus, plural light beams 10, 11 having wavelength of very close wavelength interval of about several nanometers can be separated and detected at high resolution and demodulated to electric signals independently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical transmission device, and particularly to wavelength multiplexed optical transmission in which a plurality of light beams having different wavelengths are transmitted through a single optical fiber. The present invention relates to an optical transmission device suitable for.

[Conventional technology]

Significantly improved transmission capacity in optical transmission equipment that converts electrical signals into optical pulse signals and transmits them to optical fiber transmission lines.
Wavelength multiplexing optical transmission systems are attracting attention as a technology that responds to needs such as ultra-high bandwidth signals.

In this method, on the transmitting side, multiple semiconductor laser beams (hereinafter simply referred to as laser beams) having different wavelengths are independently modulated into optical pulse signals using multiple input electrical signals, and then the optical beams are combined. The optical pulse signal of the transmitted laser light is transmitted through the same optical fiber.
On the receiving side, each wavelength is separated and detected again and demodulated independently into electrical signals.

The number of multiplexed channels in the wavelength division multiplexing optical transmission system currently in practical use is only a few channels at most. Multiplexing of hundreds of channels) is strongly desired.

In order to achieve ultra-high multiplexing of such wavelength-multiplexed optical transmission, it is necessary to ensure the emission wavelength range of the light source and the detectable wavelength range of the photodetector, the transmission loss of the transmission optical fiber, and the influence of wavelength dependence. In consideration of suppression, it is necessary to multiplex transmit a plurality of laser beams having extremely close wavelengths with a wavelength interval of several nanometers (nm) or less.

On the other hand, the demultiplexing means (demultiplexer) used in the receiving device of such a multiplexed optical transmission device includes a prism, a diffraction grating,
Spectroscopic devices using dielectric multilayer films have been devised and put into practical use.

Examples of documents that describe the configuration of the demultiplexing means (demultiplexer) in conventional wavelength division multiplexing optical transmission equipment include Ken Noda (ed.) New Edition Optical Fiber Transmission, edited by the Institute of Electronics and Communication Engineers (197
7 years), P, 331-332.

[Problem that the invention seeks to solve]

By the way, all of these demultiplexing means, that is, spectroscopic devices, become larger and more complex as the number of channels of multiplexed signals increases and the wavelength interval of each laser beam becomes narrower.
There is a limit to the resolution of spectroscopy, and it is extremely difficult to separate laser beams with wavelengths that are very close to each other, with a wavelength interval of several nanometers or less.

Therefore, with conventional spectroscopic devices, it has not been possible to construct a wavelength multiplexed optical transmission device with ultra-high multiplexing as described above.

The present invention has been made in order to solve the problems of the prior art described above, and has a simple configuration and allows multiple light beams having very close wavelengths with a wavelength interval of several nanometers or less to be transmitted. The object of the present invention is to provide a wavelength multiplexing optical transmission device equipped with a high-resolution wavelength selection filter capable of selective separation.

[Means for solving problems]

In order to solve the above-mentioned problems, the configuration of an optical transmission device according to the present invention includes an optical pulse signal transmitting device having a plurality of light sources having different wavelengths, and each output optical pulse signal of the optical pulse signal transmitting device. An optical transmission line that has an optical fiber for wavelength division multiplexing transmission from the transmitting end to the receiving end, and an optical pulse signal reception that independently converts each output optical pulse signal sent from the receiving end of this optical transmission line into an electrical signal. In the optical transmission device, at least the optical pulse signal receiving device selectively steeply reduces the light absorption rate for each wavelength of a plurality of light beams having different wavelengths by photochemical hole burning. A wavelength selection filter made of a medium is provided.

The optical pulse signal receiving device includes a splitter that splits a light beam transmitted through a wavelength division multiplexing optical fiber, a fiber lens array that has a plurality of fiber lenses arranged to output one split light beam, and a fiber lens array that arranges a plurality of fiber lenses that output one split light beam. A wavelength selective filter array includes a plurality of wavelength selective filters that selectively steeply reduce the absorption rate of light for each light beam, and a plurality of light beams that independently enter the light beams that have passed through these multiple wavelength selective filters. It is equipped with a photodetector array in which detectors are arranged.

In addition, I would like to add the idea behind developing the present invention.

It is as follows.

In the present invention, the light absorption rate of the medium is

We considered using a phenomenon called photochemical hole burning, in which light of a certain wavelength drops sharply in an extremely narrow wavelength width of lnm or less, and using a medium with such properties as a wavelength selection filter.

That is, the present invention provides at least a light pulse signal receiving device of a wavelength division multiplexing optical transmission device, by photochemical hole burning, so that only a laser beam having a specific wavelength among the multiplexed optical beams, for example, is The absorption rate of the laser beam sharply decreases, and the transmittance or reflectance of the laser beam sharply increases. A plurality of wavelength selection filter arrays are provided.

[Effect]

The technical means of such a configuration brings about the following effects.

A plurality of light beams having different wavelengths, each having an electrical signal independently modulated by the optical pulse signal transmitting device, travels through the optical fiber for wavelength multiplexing transmission, reaches the distributor of the optical pulse signal receiving device, and is connected to a fiber lens array. It is approximately evenly distributed in each array. The distributed light beams pass through a wavelength selection filter array that utilizes the photochemical hole burning phenomenon, and each light beam of a specific wavelength is made incident on each photodetector of the optical array corresponding to each wavelength selection filter.

This makes it possible to separate and detect a plurality of light beams having very close wavelengths with a wavelength interval of several nanometers with good resolution, and independently demodulate them into electrical signals.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a perspective view showing the configuration of an optical pulse signal receiving device section of an optical transmission device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining the photochemical hole burning used in the present invention, FIG. 3 is an explanatory diagram for explaining the principle of the wavelength selection filter in the apparatus of FIG. 1,
FIG. 4 is a schematic configuration diagram showing an embodiment of the procedure for creating the wavelength selection filter, and the same parts are indicated by the same reference numerals in each figure.

First, the configuration of the optical pulse signal receiving device will be explained with reference to FIG.

In FIG. 1, reference numeral 1 denotes an optical fiber for wavelength multiplexing transmission for transmitting optical pulse signals from a transmitting end to a receiving end, and this optical fiber 1 for wavelength multiplexing transmission relates to a light beam for transmitting optical pulse signals. A light beam 10, which is a combination of a plurality of light beams having different wavelengths, is transmitted as shown by the arrow.

Reference numeral 2 denotes a distributor that almost evenly distributes the light beam 10, and this distributor 2 has a function of almost evenly distributing the intensity of the light beam 10 and transmitting it to the fiber lens array 3.

3 is a fiber lens array in which a plurality of fiber lenses are arranged to emit one distributed light beam; 4 is a plurality of wavelength selection filters that selectively steeply decreases the light absorption rate for each distributed light beam 11; 5 is a wavelength selective filter array arranged with.

This is a photodetector array in which a plurality of photodetectors are arranged, each of which allows light beams that have passed through a plurality of wavelength selection filters to be incident independently.

The wavelength selection filter array 4 is configured such that the light beams 11 that are emitted from each of the seven eyeper lenses (for example, 3a) and incident on the corresponding photodetectors (for example, 5a) are selected by the corresponding wavelengths in the wavelength selection filter array 4. filter (e.g. 4a
) is arranged so that it is transparent.

Each filter of the wavelength selection filter array 4 is made of a medium (for example, a polymeric organic compound) that generates a phenomenon called photochemical hole burning, and each filter is connected to each other that is transmitted through the optical fiber 1 for wavelength multiplexing transmission. The light absorption rate decreases sharply only for a light beam of a specific wavelength among multiple light beams with different wavelengths, and the transmittance (
or reflectance) has the function of rapidly increasing.

In this way, the distributor 2, the fiber lens array 3, the wavelength selective filter array 4. The photodetector array 5 constitutes an optical pulse signal transmitter 41 .

Next, the photochemical hole burning phenomenon will be explained with reference to FIG.

The absorption spectrum of the medium that is to become a filter is shown in Figure 2 (
Consider a case where a collection of absorption lines with a narrow linewidth ΔWh results in a spectral distribution with a relatively wide linewidth ΔWl, as shown in a).

Such an absorption spectrum is observed in many substances such as amorphous and organic compounds, and the width ΔWl of the entire absorption spectrum arises from the fact that the environments of individual molecules exhibiting absorption are slightly different from each other.

When irradiated with a strong laser beam that can be tuned to any wavelength in this absorption spectrum, molecules that have absorbed that wavelength change from the ground state, which is the steady state with the lowest energy, to an excited state with higher energy than the ground state. and enters another steady state, a metastable state. Therefore, the absorption of light at that wavelength decreases or disappears, and the absorption Ifl spectrum changes to 2ΔW1. as shown in FIG. 2(b). A depression (hole) is formed with a line width corresponding to .

When a medium with an absorption spectrum in which such holes are formed is irradiated with relatively weak light that does not change the energy state of the molecules of the medium, only the light with the wavelength in which holes are formed will be irradiated. , the light transmittance or reflectance of the medium increases sharply. In other words, the light absorption rate of the medium decreases sharply. This phenomenon is called photochemical hole burning.

Holes in the absorption spectrum produced by this photochemical hole burning generally have a very narrow linewidth of about 1×m or less. Therefore, by utilizing this photochemical hole burning phenomenon, it is possible to form a wavelength selection filter with extremely high resolution.

FIG. 3 is an explanatory diagram showing the principle of a wavelength selection filter of a wavelength division multiplexing optical transmission device that utilizes the above-mentioned photochemical hole burning phenomenon, and shows the wavelength selection array 4 and photodetector array 5 shown in FIG. This is a part of the figure.

Each wavelength selection filter 4a on the wavelength selection filter array 4
, 4b, and 4c are made of a medium that exhibits the photochemical hole burning phenomenon described above. Furthermore, the light beams that have passed through the wavelength selection filters 4a, 4b, and 4c are respectively incident on the photodetectors 5a, 5b, and 5c on the photodetector array 5, where they are photoelectrically converted and the optical pulse signals are demodulated into electrical signals. detected.

Now, each of the wavelength selection filters 4a, 4b, 4c has wavelengths λl, λ2, . A light beam 11 containing a mixture of three types of light beams having a wavelength of λ3 is made incident. The intensity of the light beam 11 is assumed to be Io.

First, in the state shown in FIG. 3(a), it is assumed that each filter 4/a, 4'b, 4/c of the filter array 4' has no hole formed in its absorption spectrum. The light beams 11 transmitted through these filters 4'a, 4'b, and 4'C all have the wavelengths λ1. λ2.
The energies of the light beams with λ3 are the same,
Each photodetector 5a of the photodetector array 5 is absorbed by each filter with a similar intensity.

Reach 5b and 5c.

Next, in FIG. 3(b), for example, the wavelength selection filter 4a
is a light beam with a double wavelength, a light beam with a wavelength λ2 is sent to the wavelength selection filter 4b, and a light beam with a wavelength λ3 is sent to the wavelength selection filter 4C.
The light beams are incident on each. At this time, the intensity 11 of each light beam is stronger than the intensity 0 in the case of FIG. 3(a), and is strong enough to cause photochemical hole burning in each of the wavelength selection filters 4a, 4b, and 4c.

Due to this photochemical hole burning, the absorption rate of the wavelength selection filter 4a for the light beam having the wavelength λl decreases sharply, and accordingly, the transmittance sharply increases.

Similarly, the wavelength selection filter 4b has a steeply high transmittance for the light beam of wavelength λ2, and the wavelength selection filter 4C
The transmittance increases sharply for the light beam of wavelength λ3.

Therefore, as shown in FIG. 3(C), FIG. 3(a)
Similarly, the wavelength λ! , λ2. Even if a light beam ll containing a mixture of light beams having wavelengths λ3 is incident on the wavelength selection filters 4a, 4b, and 4c with an intensity of 0, only the light beam with the wavelength λl is selected by the wavelength selection filter 4a and the corresponding light beam is The light passes through the filter 4a and is detected by the photodetector 5a. Similarly,
The photodetector 5b detects only the light beam of wavelength 2 that has passed through the wavelength selection filter 4b, and the photodetector 5C selects and detects only the light beam of wavelength λ3 that has passed through the wavelength selection filter 4C.

The function of such a wavelength selection filter remains exactly the same no matter how many wavelengths are separated.

Next, a specific procedure for creating the wavelength selection filter array 4 will be explained with reference to FIG. 4.

First, different wavelengths λl are wavelength-multiplexed in advance.
, λ2. Laser light sources 20 a, 20 b, and 20 c each generate a light beam of λ3, and the light beams emitted from these light sources and related to the light flux that sends the optical pulse signal are arranged so as to be transmitted to the multiplexer 22. Coupling fiber lens 21a.

21b, 21C, and a multiplexer 22 provided to combine the transmitted optical beams and guide them to the optical fiber l for wavelength multiplexing transmission;
An optical fiber 1 for wavelength division multiplex transmission is provided.

Although FIG. 4 shows an example in which three light beams are multiplexed to simplify the explanation, the principle is exactly the same even when three or more light beams are multiplexed.

Next, as shown in FIGS. 4(a) to 4(c), the three V-the light sources 20a of the optical pulse signal transmitter 40.

Among the laser light sources 20b and 20c, the laser light sources shown by the solid lines are turned on one by one without modulation, so that each optical fiber IK for wavelength division multiplexing transmits a light beam of a single wavelength. That is, in FIG. 4(a), a light beam of wavelength λ3 is transmitted from the laser light source 20G to the wavelength selection filter 4C with an intensity of 1. Similarly, in FIG. 4), the laser light source 20b
In FIG. 4(C), a light beam with a wavelength λ2 is transmitted from the laser light source 20a to the wavelength selection filter 4b.
The optical beam is transmitted to the wavelength selection filter 4a.

The light beam emitted from the optical fiber 1 for wavelength division multiplexing transmission passes through each wavelength selection 7 (router 4a,
Inject into each one of 4b and 4c.

to cause photochemical hole burning so that the transmittance or reflectance for the wavelength of the light beam is maximized compared to the transmittance or reflectance for the other two wavelengths. Then, the wavelength selection filter for inputting the light beam is changed for each laser light source to be turned on, and the wavelength selection filters 4a, 4 for each of the light beams to be finally multiplexed are changed.
At least one of the filters b and 4c forms a wavelength selective filter array 4 that strongly transmits or reflects a light beam having a specific wavelength.

In FIG. 4, the wavelength selection filter 4a has a single wavelength, the wavelength selection filter 4b has a wavelength λ2, and the wavelength selection filter 4C has a wavelength λ3. Formed rel.

For the wavelength selection filter array 4 created in this way, as shown in FIG. 4(d), a distributor 2 is installed on the optical transmission path side of the wavelength selection filter array 4 as shown in FIG. , fiber lens 3a.

3b, 3c, . A receiving device 41 is configured.

If the wavelength selection filter array 4 is created using this procedure, even if the wavelengths of individual laser light sources vary from the design value, the wavelength selection filter will be suitable for the wavelength division multiplexing optical transmission device using that laser light source. Arrays can be created.

Next, the operation and effects of the optical transmission device of this embodiment will be explained with reference to FIG. 1 and FIG. 4(d).

An optical pulse signal transmitting device 40 having a laser light source that generates laser beams with different wavelengths transmits an optical pulse signal in which electrical signals are independently modulated, and the plurality of optical beams with different wavelengths are combined to form an optical beam 10. The signal is transmitted from the multiplexer 22 to the optical pulse signal receiving device 41 via the wavelength multiplex transmission optical 7-eyeper 1, which is an optical transmission line.

The light beam 10, which is a mixture of many light beams with different wavelengths, is transmitted through the optical fiber 1 for wavelength division multiplexing transmission.
It reaches the distributor 2 of the optical pulse signal receiving device 41, and each lens array 3a, 3b, 3c of the fiber lens array 3...
・Almost evenly distributed among distributed light beam 11
is each wavelength selection filter 4 of the wavelength selection filter array 4
a, 4b.

After passing through 4c..., a light beam of a specific wavelength is emitted,
The light is incident on each photodetector 5a, 5b, 5c, . . . of the photodetector array 5 corresponding to each wavelength selection filter 4a, 4b, 4c.

In this way, the optical pulse signal of the transmitted laser beam has a wavelength of λ1. λ2. Different photodetectors 5 for each λ3...
a, 5b, 5c, . . . and independently demodulated into electrical signals.

According to this embodiment, by using a wavelength selective filter array that utilizes the photochemical hole burning phenomenon,
A plurality of light beams having extremely close wavelengths with a wavelength interval of several nanometers can be separated and detected with good resolution.

Further, it is possible to construct a wavelength division multiplexing optical transmission device that is capable of ultra-high multiplexing, in which the number of channels of multiplexed optical pulse signals reaches tens to hundreds of channels, to be small and lightweight.

Next, another embodiment of the present invention will be described with reference to FIGS. 5 and 6.

FIG. 5 is a schematic configuration diagram of an optical transmission device according to another embodiment of the present invention, and FIG. 6 is a schematic diagram for explaining the function of a wavelength selection filter provided in the device of FIG. be.

In FIG. 5, parts with the same reference numerals as those in FIG. 1 and FIG. 4(d) are equivalent parts, and their explanations will be omitted.

In the embodiment shown in FIG. 5, the optical pulse signal transmitter 40' is provided with a light emitting diode array 30 as a light source.

A plurality of light emitting diodes 3 on a light emitting diode array 30
The light beams emitted from 0a, 30b, 30c, and 30d are
Similarly to the example shown in FIG. 4(d) above, each coupling fiber lens 21a.

2lb, 21c, and 21d, are combined by a multiplexer 22, and transmitted to the optical fiber 1 for wavelength multiplex transmission.

Light emitting diodes are superior in cost efficiency and reliability compared to semiconductor laser light sources and the like, and are advantageous light sources for mass production of optical transmission devices. However, on the other hand, as shown in FIG. 6(a), the emission spectrum of a light emitting diode is significantly broader than that of a laser light source, and as it is, it cannot be used as a light source for a wavelength multiplexed optical transmission device.

Therefore, in the embodiment shown in FIG. 5, the light emitting diode 30a,
30b, 30c, 30d and the coupling fiber lenses 21a, 21b, 21c, 21d, first
A wavelength selective filter array 4 as described in the illustrated embodiment was provided. As previously explained in FIGS. 2 and 3, each wavelength selection filter 4a of the wavelength selection filter array 4.

4b, 4c, and 4d, for example, as shown in the example of wavelength λl in FIG. It is something to do.

Therefore, each wavelength selection filter 4a, 4b.

The light from the light emitting diode that has passed through 4c and 4d exhibits a steep spectral distribution as shown in FIG. 6(C), for example.

The line width of this spectrum is determined by the wavelength selection filters 4a and 4b.
, 4c, and 4d, and as explained earlier in FIG. 2, it is less than 1 nm, so it is possible to obtain a substantially single-longitudinal mode light beam, similar to semiconductor laser light.

Moreover, as in the embodiment shown in FIG. 1, by shifting the wavelengths of light whose absorption rate sharply decreases for each filter, it is possible to mutually shift the wavelengths of the light emitting diode lights that have passed through each wavelength selection filter.

In the embodiment shown in FIG. 5, the optical pulse signal receiving device 41 may have the same configuration as the embodiment shown in FIG.

At this time, if the wavelength selection filter array 4 in the optical pulse signal receiving device 41 is an array having the same wavelength selectivity as the wavelength selection filter array 4 in the optical pulse signal transmitting device 40', optimal wavelength selection performance can be obtained. be able to.

In the embodiment shown in FIG. 5, the wavelength selection filter array 4 in the optical pulse signal transmitting device 40' includes a light emitting diode array 30 and a coupling fiber V7 21a,
2 l b, 21 c, 21 d, but is not limited thereto.

Fiber lenses 21 a, 2 l b, 2
1 c.

21d and the demultiplexer 22, each optical beam passes through the multiplexer 22.
They may be placed anywhere before being combined.

According to the embodiment shown in FIG. 5, the same effects as the embodiments shown in FIG. 1 and FIG. Compared to semiconductor lasers, the introduction of
It becomes possible to perform wavelength multiplexed optical transmission using highly economical light emitting diodes.

Therefore, it is possible to contribute to a dramatic improvement in the transmission capacity and widening of the bandwidth of the optical transmission device.

In the embodiment shown in FIG. 1, each wavelength selection filter of the wavelength selection filter array is of a transmission type. However, the present invention is not limited to this, and reflective wavelength selection filters may be used. It's okay.

In this case, in order to improve the efficiency, it may be possible to form a reflective film on the rear surface of the wavelength selection filter.

When using reflective wavelength selection filters, the photodetector array should be placed at a position where the light beam reflected by each of the reflective wavelength selection filters can be incident on each photodetector. Not even.

Furthermore, the fiber laser array, wavelength selection filter array, photodetector array, etc. are not limited to a two-dimensional array as shown in FIG. 1, but may be a one-dimensional array in which each element is arranged in one row.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to selectively separate a large number of light beams having very close wavelengths with a wavelength interval of several nanometers or less with a simple configuration. A wavelength multiplexing optical transmission device equipped with a high-resolution wavelength selection filter can be provided.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of an optical pulse signal receiving device section of an optical transmission device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram for explaining photochemical hole burning used in the present invention. 3 are explanatory diagrams for explaining the principle of the wavelength selection filter in the apparatus shown in FIG. 1, and FIG. 5 is a schematic configuration diagram of an optical transmission device according to another embodiment of the present invention, and FIG. 6 is a schematic diagram 1 for explaining the function of a wavelength selection filter provided in the device of FIG. 5. - Optical fiber for wavelength division multiplexing transmission, 2... distributor, 3... fiber lens array 1 3a, 3b, 3c. 3d...Fiber lens, 4...Wavelength selection filter array, 4a, 4b, 4c, 4d...Wavelength selection filter, 5...Photodetector array, 5a, 5b+
5 c+5d-...Photodetector, 10.11-...Light beam, 20a. 20b, 20cm-・v-the light source, 21a, 2
lb. 21G, 21d...Fiber lenses for coupling. 22... Multiplexer, 30... Light emitting diode array,
30a, 30b, 30c, 30d --- Light emitting diode, 40. 40'... Optical pulse signal transmitter, 41 (and other □ names) f'f'-Tunhaya l Closed A left 3°°° J Marensvrei 3C・7 Ai Harensu 4 Mugi distortion 3! Mabefil Guatoi 4tL 5 Yoshichoen [-Translation filter ((L) 3rd entry (a,) 4th day (b) Early 5th day

Claims (1)

[Scope of Claims] 1. An optical pulse signal transmitting device having a plurality of light sources with different wavelengths, and a wavelength multiplexing transmission light for transmitting each output optical pulse signal of the optical pulse signal transmitting device from a transmitting end to a receiving end. An optical transmission device comprising an optical transmission line having a fiber and an optical pulse signal receiving device that independently converts each output optical pulse signal sent from a receiving end of the optical transmission line into an electrical signal, at least Pulse signal receiver,
1. An optical transmission device comprising a wavelength selection filter made of a medium that selectively sharply reduces the absorption rate of light by photochemical hole burning for each wavelength of a plurality of light beams having different wavelengths. 2. In the device described in claim 1, the optical pulse signal receiving device includes a distributor that distributes the optical beam transmitted through the optical fiber for wavelength division multiplexing transmission, and a plurality of optical pulse signal receivers that output the distributed optical beam. a fiber lens array in which fiber lenses are arranged, a wavelength selective filter array in which a plurality of wavelength selective filters are arranged to selectively steeply reduce the light absorption rate for each distributed light beam, and these plural wavelength selective filters. An optical transmission device that is equipped with a photodetector array in which a plurality of photodetectors are arranged, each of which allows a light beam to be incident independently. 3. In the device described in claim 1, the optical pulse signal transmitting device includes a plurality of laser light sources that generate laser light with different wavelengths, and a wavelength multiplexing method that combines and wavelength-multiplexes the plurality of light beams from these laser light sources. An optical transmission device that is equipped with a multiplexer for guiding to an optical fiber for transmission. 4. In the device described in claim 1, the optical pulse signal transmitting device includes a light emitting diode array in which a plurality of light emitting diodes are arranged, and a light beam selectively transmitting a light beam emitted by the light emitting diodes. A wavelength selection filter array that has multiple wavelength selection filters that sharply reduce the absorption rate of light, and a multiplexer that combines the multiple light beams that have passed through these wavelength selection filters and guides them to an optical fiber for wavelength multiplexing transmission. An optical transmission device that is equipped with: