JP3910103B2 - Optical transceiver - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical transmitter / receiver, and more particularly to an optical transmitter / receiver that is small and can be manufactured at low cost.
[0002]
[Prior art]
A conventional optical transceiver is shown in FIG. The optical transmitter / receiver 20 makes light having a wavelength λ1 (for example, λ1 = 1310 nm) emitted from a laser diode 11 as a light emitting element incident on the optical fiber 12 and a wavelength λ2 (for example, λ2 = emitted) from the optical fiber 12. 1550 nm) is received by the photodiode 13 which is a light receiving element.
[0003]
The optical transmitter / receiver 20 is close to the first collimation lens 21 provided close to the laser diode 11, the second collimation lens 22 provided close to the optical fiber 12, and the photodiode 13. A third collimation lens 23 provided, and a multilayer filter 24 acting as a dichroic mirror disposed between the first and second collimation lenses 21 and 22 with an inclination of 45 degrees with respect to the optical axis. ing.
[0004]
According to the optical transmitter / receiver 20, the light of wavelength λ1 emitted from the light emitting element 15 of the laser diode 11 is converted into parallel light by the first collimation lens 21, passes through the multilayer filter 24, and is subjected to the second collimation. The light is condensed by the lens 22 and enters the optical fiber 12.
[0005]
In addition, the light of wavelength λ2 emitted from the optical fiber 12 is converted into parallel light by the second collimation lens 22, reflected by the multilayer filter 24, collected by the third collimation lens 23, and collected by the photodiode 13. The light enters the light receiving element 14.
[0006]
[Problems to be solved by the invention]
By the way, the conventional optical transceiver described above uses three collimation lenses 21, 22, 23 and a multilayer filter 24, and has a large number of parts. For this reason, there is a problem that the parts cost increases and the apparatus becomes large. Furthermore, there is a problem that it takes time to adjust the position of each member.
[0007]
Accordingly, an object of the present invention is to provide an optical transmission / reception apparatus that is small in size, has a small number of parts, and is low in cost.
[0008]
[Means for Solving the Problems]
In the present invention, in order to solve the above-described problems, an optical transceiver is configured as follows. The present invention includes a light emitting element that emits light of a first wavelength and a light receiving element that receives light of a second wavelength, and the light from the light emitting element is incident on an optical fiber, and the light from the optical fiber is An optical transmission / reception apparatus comprising an optical circuit element incident on the light receiving element, wherein the optical circuit element includes first and second optical elements, and the first optical element is formed of an optical material. A first lens surface that collimates the divergent light from the light emitting element and a second lens surface that condenses the light from the optical fiber that has passed through the second optical element on the light receiving element. The second optical element includes a third lens surface for condensing light from the first lens surface onto an optical fiber on a base formed of an optical material, and a first lens surface from the first lens surface. First-order diffraction of light from the optical fiber while emitting 0th-order transmitted light to the optical fiber A diffraction grating surface that emits light in a predetermined direction, and the light from the light emitting element is incident on the optical fiber by the first optical element and the second optical element, and the light from the optical fiber is incident on the second optical element. An optical receiver that diffracts on the diffraction grating surface of the optical element, emits the light toward the first optical element, and makes the diffracted light incident on the light receiving element.
[0009]
According to the present invention, in the first optical element, the first and second lens surfaces are formed on the substrate formed of the optical material, and divergent light from the light emitting element is generated on the first lens surface. The light from the optical fiber that has been converted into parallel light and passed through the first optical element on the second lens surface is condensed on the light receiving element. For this reason, it is not necessary to provide a collimator lens as a separate member in the optical transmission / reception apparatus, the procedure can be simplified, such as a reduction in the size of the apparatus, a reduction in the number of parts, and a position adjustment during assembly.
[0010]
In the optical transceiver according to the present invention, the first optical element can be provided with a reflecting surface that reflects the first-order diffracted light toward the second lens surface.
[0011]
According to the present invention, since the first-order diffracted light of the transmission light from the optical fiber is reflected toward the second lens surface by the reflection surface of the first optical element, the arrangement position of the light emitting element and the arrangement of the light receiving element It is possible to increase the degree of freedom in designing the optical transceiver.
[0012]
Furthermore, in the optical transceiver according to the present invention, the diffraction grating surface of the second optical element can be provided to face the optical fiber.
[0013]
According to the present invention, the first-order diffracted light is incident on the second optical element with good efficiency from the optical fiber.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an embodiment of an optical transceiver 30 according to the present invention.
[0014]
In this example, light having a first wavelength (for example, λ = 1310 nm) from the light emitting element 15 of the laser diode 11 that is a light emitting element is incident on the optical fiber 12 and a second wavelength (for example, emitted from the optical fiber 12). (λ = 1550 nm) is incident on the light receiving element 14 of the photodiode 13 which is a light receiving element.
[0015]
In this example, the optical transceiver 30 includes a first optical element 40 and a second optical element 50 between the laser diode 11 and the optical fiber 12.
[0016]
In this example, the first optical element 40 is formed by integrally forming an optical material such as an optical synthetic resin or optical glass. As shown in FIG. 2, the first optical element 40 is disposed on the base 41 so as to be perpendicular to the optical axis O of the optical fiber 12 and coaxially with the optical axis O. The 1st lens surface 42 which makes the diverging light from the light emitting element 11 parallel light is formed.
[0017]
The first optical element 40 includes a second lens surface 43 that condenses the light from the optical fiber 12 that has passed through the second optical element 50 onto the photodiode 13, and the second optical element 50. And a reflecting surface 45 that totally reflects the first-order diffracted light toward the second lens surface 43.
[0018]
Further, as shown in FIG. 3, the second optical element 50 is formed of an optical synthetic resin or optical glass as an optical material, and a laser diode is formed on the surface of the base 51 facing the laser diode 11. 11 and a third lens surface 52 that is a positive lens that condenses the light that has passed through the first lens surface 42 on the optical fiber 12.
[0019]
Furthermore, the light from the first lens surface 42 is emitted to the optical fiber 12 as zero-order transmitted light on the surface of the second optical element 50 that faces the optical fiber 12, and from the optical fiber 12. A diffraction grating surface 53 that emits first-order diffracted light in a predetermined direction is provided. The pitch and shape of the diffraction grating 53 can be appropriately selected as design matters.
[0020]
According to this example, the light from the light emitting element 11 is incident on the optical fiber 12 by the first optical element 40 and the second optical element 50, and the light from the optical fiber 12 is the second optical element. The light is diffracted by the diffraction grating surface 53 of the element 50, and the first-order diffracted light is directed to the first optical element.
[0021]
According to this example, it is not necessary to provide a collimator lens as a separate member in the optical transmission / reception apparatus, the apparatus size can be reduced, the number of parts can be reduced, and procedures such as position adjustment during assembly can be simplified, thereby reducing apparatus manufacturing costs. I can plan.
[0022]
In this example, the diffraction grating surface 33 is a so-called step-like diffraction grating surface that transmits light having a predetermined wavelength λ1 = 1310 nm and first-order diffracts light having a wavelength λ2 = 1550 nm at a predetermined angle. Note that the first wavelength and the second wavelength can be interchanged.
[0023]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and can be modified without departing from the gist thereof.
[0024]
【The invention's effect】
As described above, according to the optical transceiver according to the present invention, the following excellent effects can be obtained.
[0025]
According to the present invention, in the first optical element, the first and second lens surfaces are formed on the substrate formed of the optical material, and divergent light from the light emitting element is generated on the first lens surface. The light from the optical fiber that has been converted into parallel light and passed through the first optical element on the second lens surface is condensed on the light receiving element. For this reason, it is not necessary to provide a collimator lens as a separate member in the optical transmission / reception device, and the procedure for reducing the size of the device, reducing the number of components, and adjusting the position at the time of assembly can be simplified, and the cost of manufacturing the device can be reduced.
[0026]
In addition, according to the present invention, the first-order diffracted light of the transmission light from the optical fiber is reflected toward the second lens surface by the reflection surface of the first optical element. The arrangement position can be separated, and the degree of freedom in designing the optical transmission / reception apparatus can be increased.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an optical transceiver according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a first optical element of the optical transmission / reception apparatus illustrated in FIG. 1;
3 is an enlarged view showing a second optical element of the optical transmission / reception apparatus shown in FIG. 1. FIG.
FIG. 4 is a diagram illustrating a conventional optical transceiver.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Laser diode 12 Optical fiber 13 Photodiode 14 Light receiving element 15 Light emitting element 20 Optical transmission / reception apparatus 21 Collimation lens 22 Collimation lens 23 Collimation lens 24 Multilayer filter 30 Optical transmission / reception apparatus 31 Base 32 Convex lens surface 33 Diffraction grating surface 34 Reflection surface 36 Convex lens Surface 40 Optical element 41 Base 42 Lens surface 43 Lens surface 44 Incident surface 45 Reflecting surface 50 Optical element 51 Base 52 Lens surface 53 Diffraction grating 53 Diffraction grating surface

Claims (3)

A light-emitting element that emits light of a first wavelength; and a light-receiving element that receives light of a second wavelength. The light from the light-emitting element is incident on an optical fiber, and the light from the optical fiber is incident on the light-receiving element. An optical transmitter / receiver comprising an incident optical circuit element,
The optical circuit element comprises first and second optical elements,
The first optical element has a base formed of an optical material, a first lens surface that makes the divergent light from the light emitting element parallel light, and the light from the optical fiber that has passed through the second optical element. A second lens surface for condensing the light receiving element,
The second optical element has a base formed of an optical material, a third lens surface for condensing light from the first lens surface onto an optical fiber, and light from the first lens surface. A diffraction grating surface that emits the first-order diffracted light of the light from the optical fiber in a predetermined direction as it is emitted to the optical fiber as 0th-order transmitted light,
The light from the light emitting element is incident on the optical fiber by the first optical element and the second optical element, and the light from the optical fiber is diffracted by the diffraction grating surface of the second optical element. To the optical element of
An optical receiver that makes this diffracted light incident on a light receiving element. The optical transmission / reception apparatus according to claim 1, wherein the first optical element includes a reflection surface that reflects the first-order diffracted light toward the second lens surface. The optical transmission / reception apparatus according to claim 1, wherein a diffraction grating surface of the second optical element is provided to face the optical fiber.

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