KR20160128675A - Wavelength tunable bidirectional optical subassembly - Google Patents

Abstract

The present invention relates to a wavelength tunable bidirectional optical subassembly (BOSA) for an optical transceiver. More specifically, the present invention relates to a wavelength tunable BOSA for an optical transceiver, capable of implementing the bidirectional BOSA irrespectively of a wavelength by using an optical circulator instead of a band-pass wavelength filter to overcome a disadvantage that wavelengths of upstream and downstream optical signals are limited, which is a disadvantage of a BOSA using a conventional band-pass wavelength filter, and implementing an identical function without requiring an additional optical isolator, unlike a conventional wavelength tunable BOSA which essentially requires to use an optical isolator. The BOSA includes: a wavelength tunable laser; a first lens; an optical circulator; a second lens; an optical fiber; and a third lens.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a wavelength tunable bidirectional optical subassembly for a bidirectional wavelength tunable optical transceiver,

The present invention relates to an optical submodule for a wavelength-tunable optical transceiver having a bidirectional structure, and more particularly, to an optical submodule for a bidirectional optical transceiver, which is a disadvantage of a bidirectional optical subassembly (BOSA) using a conventional band- In order to overcome the disadvantage that the wavelength is limited, a bidirectional BOSA can be implemented regardless of the wavelength by using a optical circulator instead of a band-pass wavelength filter, and a conventional optical isolator Modulated optical transceiver having a bidirectional structure that can implement the same function without the need for a separate optical isolator, unlike the tunable BOSA of the wavelength tunable optical transceiver.

WDM (Wavelength Division Multiplexing) optical communication technology is currently applied to most backbone networks and metro networks, and is a technology for transmitting a plurality of high-speed signals by wavelength division multiplexing to an optical fiber composed of one optical fiber. In the WDM transmission network, an optical add / drop multiplexer (OADM) function capable of selectively branching / combining a part of the lightwaves without photoelectric conversion is required.

The OADM can extend the connectivity of the network and increase its efficiency by connecting the intermediate nodes in the transmission line in wavelength units.

ROADM (Reconfigurable OADM) is able to reconfigure the branching / coupling wavelength of nodes at the remote site without the input of specialist technicians and efficiently reconfiguring the wavelength connection state of the whole network, The maintenance cost can be drastically reduced.

Recently, Bidirectional optical subassembly (BOSA) using wavelength tunable lasers has been attempted to reduce the inventory burden and the operating cost while increasing the flexibility of the transmission network.

1 is a view for explaining the operation of a conventional BOSA using a band pass filter. As shown in FIG. 1, an upstream signal emitted from a wavelength variable light source (generally, a wavelength tunable BOSA is located in a subscriber magnetic field, so that light emitted from the upstream side of the emitted light is referred to as a downstream signal for convenience). The wavelength band of the wavelength-tunable light source is reversed and the wavelength band of the downstream signal is incident on the optical fiber through the band-pass filter which reflects the wavelength band.

On the other hand, the downstream signal, which is incident light coming from the optical fiber to the BOSA, is reflected by the bandpass filter and detected by the photodetector and converted into an electric signal.

In general BOSA as described above, the wavelength bands of the upstream and downstream signals must be set to be different from each other. If the same wavelength band is used, the BOSA does not operate due to noise such as crosstalk. In addition, if the band of upstream and downstream signals used is close, the 45-degree filter can not be used. Therefore, the position of the photodetector should be located at an acute angle rather than a vertical direction, or one mirror should be further installed in the BOSA.

The BOSA using such a wideband transmission filter makes it difficult to select a wavelength to be used, and accordingly, wavelength provisioning needs to be precisely performed, thereby increasing operating costs.

On the other hand, in Korean Patent No. 10-0637928 (hereinafter referred to as "wavelength tunable transmission / reception module ", hereinafter referred to as Prior Art 1), wavelength tuning is possible in a wide wavelength region of C band, Module.

Korean Registered Patent No. 10-0637928 (Registered on October 17, 2006)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art as described above, and it is an object of the present invention to provide an optical communication system, which is a disadvantage of Bidirectional optical subassembly using a band- In order to overcome the disadvantage that the wavelength is limited, a bidirectional BOSA can be implemented regardless of the wavelength by using a optical circulator instead of a band-pass wavelength filter, and an optical isolator must be used The present invention is to provide an optical submodule for a wavelength tunable optical transceiver having a bidirectional structure that can implement the same function without requiring a separate optical isolator, unlike the conventional wavelength tunable BOSA.

The optical submodule for a wavelength tunable optical transceiver having a bidirectional structure according to an exemplary embodiment of the present invention is a Bidirectional optical subassembly (BOSA) that operates a bidirectional signal emitted from a wavelength variable light source regardless of wavelengths used, A first lens 210 for converting the wavelength tunable laser 100 into a parallel light and a second lens 210 for converting the wavelength tunable laser 100 into parallel light when the light passing through the first lens 210 enters the first port 310. [ The optical circulator 500 for outputting the upward signal from the second port 320 to the optical fiber 400 regardless of the polarization direction of the input light to the second port 320 at which the optical fiber 400 is positioned, A second lens 220, an optical fiber 400 for transmitting upward light that has passed through the second lens 220 to a remote location, and an optical fiber 400 for converting light of a downstream signal received from a remote site through the optical fiber 400 into parallel light 3 lens 230 And the optical circulator 500 transmits the downstream signal to the third port in the direction of the photodetector 600 when the downstream signal is incident on the second port 320. The BOSA transmits the optical circulator 500, And a photodetector 600 for converting light from the third port 330 to an electrical signal through the second port 500.

The optical submodule for a wavelength tunable optical transceiver having the above-described bidirectional structure of the present invention can be used for a wide range of wavelengths for uplink and downlink optical signals, which are disadvantages of Bidirectional optical subassembly (BOSA) using a conventional band- In order to overcome the disadvantage that the wavelength is limited, a bidirectional BOSA can be realized regardless of wavelength by using a optical circulator instead of a band-pass wavelength filter.

Unlike the conventional wavelength tunable BOSA which must use an optical isolator, the same function can be realized without a separate optical isolator, which is advantageous in efficiency.

1 is a view for explaining an operation of a conventional BOSA using a band-pass wavelength filter.
FIG. 2 is a flowchart illustrating an operation of a BOSA in which a bidirectional signal emitted from a wavelength variable light source, which is an optical submodule for a wavelength variable optical transceiver having a bidirectional structure using a optical circulator according to an embodiment of the present invention, FIG.

Hereinafter, an optical submodule for a wavelength tunable optical transceiver having a bidirectional structure according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The following drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the following drawings, but may be embodied in other forms. In addition, like reference numerals designate like elements throughout the specification.

In this case, unless otherwise defined, technical terms and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the following description and the accompanying drawings, A description of known functions and configurations that may unnecessarily obscure the description of the present invention will be omitted.

The optical submodule for a wavelength tunable optical transceiver having the bidirectional structure of the present invention has a disadvantage in that the wavelength of upstream and downstream optical signals, which is a disadvantage of Bidirectional optical subassembly (BOSA) using a conventional band-pass wavelength filter, In order to overcome this problem, unlike the conventional wavelength tunable BOSA, which can implement a bidirectional BOSA regardless of wavelength by using a optical circulator instead of a band-pass wavelength filter and must use an optical isolator, Is an optical submodule for a wavelength tunable optical transceiver having a bidirectional structure capable of implementing the same function without requiring a separate optical isolator.

As shown in FIG. 2, the BOSA (Bidirectional optical subassembly) is a BOSA (bidirectional optical subassembly) that operates in a bidirectional signal emitted from a wavelength variable light source irrespective of wavelengths used. The wavelength tunable laser 100, the first through third lenses 210 230, the first to third ports 310 to 330, the optical fiber 400, and the optical circulator 500.

Referring to FIG. 2, an optical submodule for a wavelength tunable optical transceiver having a bidirectional structure according to an exemplary embodiment of the present invention, that is, a bidirectional optical signal output from a wavelength variable light source, subassembly will be described in detail.

It is preferable that the wavelength tunable laser of the BOSA operating in the bidirectional signal emitted from the wavelength variable light source of the present invention is used as an upstream signal.

The first lens 210 serves to convert the wavelength tunable laser 100 into parallel light.

When the light passing through the first lens 210 is incident on the first port 310, the optical circulator 500 may transmit the light to the second port 320 where the light delimiter 400 is located, ).

At this time, the second lens 220 may connect an upward signal from the second port 320 to the optical fiber,

The optical delimiter (400) may carry upward light passing through the second lens (220) remotely

The third lens 230 converts light of a downstream signal incident from a remote place into parallel light through the optical fiber 400,

In this case, when the downstream signal input through the third lens 230 is incident on the second port 320, the optical circulator 500 transmits the third signal through the third port 330, which is the direction of the photodetector 600, .

Therefore, the photodetector 600 can convert the light that has passed through the optical circulator 500 to the third port 330 into an electrical signal.

That is, in other words, in the BOSA which operates the bidirectional signal emitted from the wavelength variable light source of the present invention irrespective of the wavelength used, the upstream signal emitted from the wavelength variable light source is incident on the first port of the optical circulator, .

Also, the downstream signal input to the second port is output to the third port of the optical circulator, and the light output through the third port is converted into the electric signal by the photodetector.

Accordingly, in the conventional BOSA, the wavelength bands of the upstream and downstream signals must be set to be different from each other. When using the same wavelength band, operation is difficult due to noise such as crosstalk,

The BOSA, which operates the bidirectional signal emitted from the wavelength variable light source of the present invention irrespective of the wavelength used, is advantageous in that it operates easily regardless of the wavelengths of the upstream and downstream signals through the optical circulator.

As described above, the present invention has been described with reference to specific embodiments such as specific components and exemplary embodiments. However, the present invention is not limited to the above-described embodiments, And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, fall within the scope of the present invention .

100: wavelength tunable laser
210: first lens 220: second lens
230: Third lens
310: first port 320: second port
330: Third port
400: Optical fiber
500: Optical Circulator
600: photodetector

Claims (1)

Bidirectional optical subassembly (BOSA) that operates on a bidirectional signal emitted from a wavelength variable light source regardless of wavelength used,
A tunable laser 100 used as an upstream signal;
A first lens 210 for converting the wavelength tunable laser 100 into parallel light;
The optical circulator 320 outputs the optical signal to the second port 320 where the optical fiber 400 is positioned regardless of the polarization direction of the input light when the light passing through the first lens 210 is incident on the first port 310. [ Circulator 500;
A second lens 220 connecting an upward signal from the second port 320 to an optical fiber;
An optical fiber (400) for carrying upward light passing through the second lens (220) to a remote location; And
A third lens 230 for converting light of a downstream signal incident from a remote site into parallel light through the optical fiber 400;
And,
The optical circulator 500 includes:
When the downstream signal is incident on the second port 320, the downstream signal is transmitted to the third port in the direction of the photodetector 600,
The BOSA
A photodetector 600 for converting the light passing through the optical circulator 500 to the third port 330 into an electrical signal;
Wherein the wavelength-tunable light source is a two-way signal operated by the BOSA regardless of the wavelength used.

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