JP3157852B2 - Unidirectional optical transmission module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-way optical transmission module, and more particularly, to a one-way optical transmission module used for wavelength division multiplex communication for transmitting a plurality of different optical information at the same time.

[0002]

2. Description of the Related Art Conventionally, there is an optical transmission method using a semiconductor laser as shown in FIG. The optical transmission method is as follows. That is, the light P ₀ emitted from the semiconductor laser chip 51 enters the optical fiber 54 from the incident end 53 directly or through the optical system 52. Then, the light is emitted to the emission end 55 while being totally reflected in the optical fiber 54. Then, the light P ₀ is transmitted directly or through the optical system 5.
6, and enters the signal receiving photodiode 57;
Transmit optical information.

[0003] Further, when simultaneously transmitting a plurality of different information, a method of arranging a plurality of unidirectional optical transmission modules 58 in parallel as shown in FIG. Alternatively, as a method for performing wavelength multiplex communication, a method as shown in FIG. 5 is known. That is, different wavelengths (λ ₁
(Λ ₂ ) The laser beams emitted from the two types of semiconductor laser chips 59 and 60 are combined into one by an optical element 61 such as a diffraction grating, and are incident on an optical fiber 62 and propagated. The laser light emitted from the optical fiber 62 has respective wavelengths (λ ₁ λ ₂ ) by an optical element 63 such as a diffraction grating.
After being distributed to the photodiodes 64.6 for signal reception
5 is incident.

[0004]

However, the optical transmission module used in the method shown in FIG. 3 has one light source for transmitting information. Therefore, if a plurality of different pieces of information are to be transmitted at the same time, it is necessary to install modules in parallel by the number of pieces of information as shown in FIG. Also, 1
For the purpose of transmitting different information simultaneously with this optical fiber,
When performing wavelength multiplexing communication as shown in FIG. 5, there are the following problems. That is, the independent light sources 59 and 60 and the diffraction grating 61 are adjusted on the transmitting unit side, and the independent light receiving photodiodes 64 and 65 and the diffraction grating 63 are adjusted on the receiving unit side so as to be coupled to the optical fiber 62, respectively. It is necessary to assemble. For this reason, the structure and manufacturing process of each unit have been complicated. In addition, when a plurality of different pieces of information are shared by one optical fiber, a time-division transmission method can be considered. In this case, however, there is a disadvantage that different pieces of information cannot be transmitted at the same time.

The present invention has been made in view of such circumstances, and provides a unidirectional optical transmission module that can easily perform wavelength division multiplexing communication with a single optical fiber while having a simple structure. The purpose is to do.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a unidirectional optical transmission module for performing wavelength division multiplexing communication, which is arranged between a transmission unit, a reception unit, and both of these units and connects both units. and a single optical fiber, transmitting unit, and two different semiconductor laser chip wavelength light on the surface of the semiconductor laser chip to monitor each of the two photodiodes and the semiconductor laser package that is die-bonded Fiber coupling
A first hologram element for light deflection on which a lens is formed , and which is integrated into two.
The laser light emitted from the chip is converted into a first optical deflection hologram.
The signal is combined by the ram element and made incident on the optical fiber, and the receiving unit performs the second optical deflection in which the optical fiber coupling lens is formed on the surface of the photodiode package on which two different signal receiving photodiodes are die- bonded. Integrated hologram element fixed
Two laser beams with different wavelengths from the optical fiber
The signal is distributed by the second light deflection hologram to receive two signals.
This is a one-way optical transmission module for making light incident on a photodiode for light.

That is, the present invention relates to an optical transmission module using a semiconductor laser package in which a hologram element having a diffraction grating pattern for deflecting a laser beam formed on the surface of a cap of a semiconductor laser is fixed. Die bond two different laser chips. On the other hand, two signal receiving photodiodes are die-bonded to the receiving module side. Then, two wavelengths are synthesized or distributed by the light deflection hologram element fixed on the cap surface. Thereby, optical coupling from the receiving module and the transmitting module to one optical fiber can be easily performed, and wavelength multiplex communication can be performed.

[0008]

With the optical transmission module according to the present invention,
In the wavelength division multiplexing communication using one optical fiber, the hologram element for light deflection, the semiconductor laser for light source and the photodiode for light reception are integrated, so that the transmission unit and the optical fiber of the optical transmission module, and the reception unit and the light Each optical coupling of the fiber can be easily performed without complicated manufacturing steps. Further, the optical positional relationship between the semiconductor laser chip and the hologram element and between the light-receiving photodiode and the hologram element becomes strong against physical disturbance. Furthermore, the quality reliability as a module can be improved.

[0009]

EXAMPLES Hereinafter, the present invention will be described in detail based on the shown to actual施例in FIG. The present invention is not intended to be thus limited to being this.

Reference Example First, FIG. 1 shows a reference example which is a basic configuration of the embodiment.
It will be described using FIG. Unidirectional optical transmission module M ₁ in FIG. 1 includes a transmitting unit 1, the receiving unit 2 and the optical fiber 22. The transmitting unit 1 includes two types of semiconductor laser chips 19 and 20 having different wavelengths, and both semiconductor laser chips 19 and 20 in the semiconductor laser package 16.
20 is integrated (in one package) in which a hologram element 21 for light deflection is fixed to the surface of a package 16 by die-bonding 20 monitoring PIN photodiodes 17 and 18. The receiving unit 2 is a photo
An integrated (one package) structure in which two different signal receiving photodiodes 24 and 25 are die-bonded to the diode package 26 and the light deflecting hologram element 23 is fixed to the surface of the package 26. It is.

The laser light P ₁ emitted from one semiconductor laser chip 19 passes through the hologram element 21 and enters the optical fiber 22. The light emitted from the optical fiber 22 is diffracted by the hologram element 23, and then enters one of the photodiodes 25 to propagate information. Laser light P emitted from the other semiconductor laser chip 20 ₂ laser light P ₁ after being diffracted incident on the hologram element 21
And the laser light P ₀ is incident on the optical fiber 22. After the light emitted from the optical fiber 22 is diffracted by the hologram element 23, the other photodiode 24
Incident on. As a result, information from the semiconductor laser chip 20 is propagated to the photodiode 24.

[0012] shows an embodiment in example Figure 2. The optical transmission module M _2, in addition to the optical deflecting function of the light deflection hologram element 21 (23), by disposing a Fresnel lens 27, thereby improving the coupling efficiency with the optical fiber. Therefore, operation and effect of the optical transmission module M ₂ is an optical transmission module
In addition to the operation and effect of Le M _1, the coupling efficiency between the optical fiber
Can be improved .

[0013]

According to the present invention, the optical coupling between the transmitting unit and the optical fiber and the optical coupling between the receiving unit and the optical fiber are achieved by a simple structure without using an optical element such as an independent diffraction grating. No complicated manufacturing process such as optical axis adjustment is required. In addition, since the hologram elements for light deflection in the transmission unit and the reception unit are integrated with the transmission unit and the reception unit, once the arrangement relationship is determined, fine adjustment of the optical axis is performed for each product. This eliminates the necessity, thereby simplifying the manufacturing process and improving the product quality. Further, the transmitting unit and the receiving unit
The optical fiber is applied to each deflecting hologram element of the knit.
Since the coupling lens is formed, separate optical fiber
The connection to the optical fiber can be made without arranging the coupling optics.
The joint efficiency can be improved. As described above, according to the present invention, wavelength multiplex communication can be easily performed with a simple structure.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the overall configuration of an optical transmission module according to a reference example of the present invention.

FIG. 2 is an explanatory diagram of a main configuration of an optical transmission module according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating the configuration of a conventional optical transmission module.

FIG. 4 is a diagram illustrating the configuration of another conventional optical transmission module.

FIG. 5 is a configuration explanatory view of still another conventional optical transmission module.

[Explanation of symbols]

 16.26 Package 17.18 Monitor PIN photodiode 19.20 Semiconductor laser chip 21.23 Optical deflecting hologram element 22 Optical fiber 24.25 Light receiving photodiode 27 Fresnel lens

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-51-132903 (JP, A) JP-A-3-44992 (JP, A) JP-A-1-313988 (JP, A) JP-A-1- 270283 (JP, A) JP-A-62-141794 (JP, A) JP-A-2-120857 (JP, U) JP-A-60-130663 (JP, U) (58) Fields investigated (Int. Cl. ^7, DB name) G02B 6/26 G02B 6/30 - 6/34 G02B 6/42 - 6/43 H01S 5/00 - 5/50

Claims (1)

(57) [Claims] 1. A one-way optical transmission module for performing wavelength division multiplexing communication, comprising: a transmitting unit, a receiving unit, and one optical fiber disposed between the two units and connecting the two units. the transmission unit includes a different two semiconductor laser chips of a wavelength, these semiconductor laser chip to monitor each of the two photodiodes and is die-bonded to the LES for optical fiber attached to the surface of the semiconductor laser package
The first optical deflection hologram element on which the lens is formed is fixed and integrated, and the two semiconductor lasers are integrated.
Laser light emitted from the laser chip to the first light deflection
And combined into the optical fiber
Is, the receiving unit, the optical fiber coupling lens is formed in two different photodiodes package surface the signal receiving photodiode is die-bonded
Der the second light deflection hologram element that is integrated formed of a fixed is, different 2 wavelengths from the optical fiber
Laser light is divided by the second light deflection hologram.
To be incident on the two signal receiving photodiodes.
One- way optical transmission module.