JPS60258506A - Optical element for multiplexing of optical wavelength - Google Patents

Abstract

PURPOSE:To obtain an optical multiplexing element where the loss of a main line system is small, by combining an opitical element which branches the incident light having an optical wavelength lambda1, an optical element which reflects the light having the optical wavelength lambda1 but permits lights having the other potical wavelengths lambda2-lambdan to pass through, and an optical waveguide. CONSTITUTION:The optical signal having optical wavelengths lambda2 and lambda4 inputted from a terminal 1 is transmitted through a plane 8 and passes points 16 and 17 and is transmitted through a plane 9 and is outputted from a terminal 3. The optical signal having optical wavelengths lambda2-lambda4 inputted form the terminal 3 passes the plane 9, points 17 and 16, and the plane 8 and is outputted from the terminal 1. The optical signal having the optical wavelength lambda1 inputted from a terminal 2 passes a point 21 and is transmitted through a plane 10 by about 50% and passes points 20 and 18 and is totally reflected on the plane 9 and is outputted from the terminal 3. The optical signal having the wavelength lambda1 reflected on the plane 10 by 50% passes points 19 and 15 and is totally reflected on the plane 18 and is outputted from the terminal 1. Planes 8 and 9 permit the optical signal having optical wavelengths lambda2-lambda4 to transmit through by 100% and reflect the optical signal having the optical wavelength lambda1 by 100%. Thus, the optical multiplexing element where the loss of the main line system is small is obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is an optical element used in an optical network using optical wavelength division multiplexing technology, in which an optical signal can be added from an optical terminal device to a main line system. The present invention relates to an optical multiplexing device with low system loss.

[Conventional technology]

Conventionally, optical elements for optical wavelength multiplexing are broadly classified into optical multiplexers and optical demultiplexers, but these elements are n:1 or 1
:n type, and it is currently rare to find one used in bus-type or loop-type optical networks.

Currently, the most important problem in systematizing optical networks using the same wavelength is the level diagram of the optical signal. Since the SA is determined by the optical reception level of the optical terminal equipment, PCM communication such as data transmission is the main focus, and each optical terminal equipment has the function of a repeater, and is an optical element that connects the main line system and each device. Usually, an optical switch, which is an active element, is used.

Therefore, there has been a drawback that it is not possible to obtain an optical multiplexing element in which an optical signal can be added to the main line system from the optical terminal equipment and the loss in the main line system is low.

[Purpose of the invention]

The purpose of the present invention is to add optical signals from optical terminal equipment to the main line system, which is necessary when adding optical signals to an optical network using optical wavelength division multiplexing technology to construct a new system. An object of the present invention is to provide an optical multiplexing element with low main line system loss.

That is, an object of the present invention is to provide an optical element that has the function of branching incident light of wavelength λ1, which is considered necessary for a new optical network using optical wavelength division multiplexing technology, and an optical element that completely reflects light wavelength λ1 and splits the incident light of wavelength λ1. An object of the present invention is to provide an optical multiplexing element in which the loss in the main line system is reduced by combining an optical element having a surface that transmits wavelengths up to λn and an optical waveguide.

[Structure of the invention]

The present invention relates to a transmission system for optical wavelength signals having optical wavelengths λ2 to λn (n: an integer of 2 or more), and an optical wavelength multiplexing optical system for inserting an optical signal having an optical wavelength λ1 different from any of the optical wavelengths. In the element, an original signal having an optical wavelength λ1 is inputted, and the optical signal split by the first optical element that splits the optical signal and the optical signal split by the -th optical element are respectively inputted, and the optical signal having an optical wavelength λ1 is inputted to the element.
and two second optical elements that completely reflect light from the wavelength λ2 to λn and completely transmit the light wavelengths λ2 to λn, the second terminals of each of the second optical elements are connected to each other, and the second optical elements are connected to each other. An optical element for wavelength multiplexing, characterized in that each terminal functions as an input/output terminal for insertion into the transmission system.

[Explanation of Examples]

The present invention will be described in detail with reference to the drawings. FIG. 1 shows a functional diagram and a configuration diagram of an optical element according to the present invention. FIG. 1(a) shows that the light wavelengths used for the large amount of light wavelength of the present invention are λ1 to λ4.
A functional diagram of the optical element is shown for the case of an optical signal.

An optical signal having an optical wavelength λ2 to λ4 input from a terminal 1 and an optical signal having an optical wavelength λ1 input from a terminal 2 are combined, and an optical signal having an optical wavelength λ1 to λ4 is output from a terminal 3.

In addition, the optical signal of optical wavelength λ2 to λ4 inputted from terminal 3 and the optical signal of optical wavelength λ1 inputted from terminal 2 are combined and output to terminal 1.
Optical signals having optical wavelengths λ1 to λ4 are outputted from.

FIG. 2(b) shows a configuration diagram of an optical element according to the present invention.

An optical signal of wavelength λ2 to λ4 inputted from terminal 1 passes through surface 8, passes through point 161 and point 17, passes through surface 9, and reaches terminal 3.
is output from. Light wavelength λ2 to λ4 input from terminal 3
The optical signal passes through 92 points, 172 points 16, and surface 8, and is output from terminal 1. The optical signal of optical wavelength λ1 inputted from terminal 2 passes through point 21, is transmitted by about 50% at surface 10, and passes through point 202.
It passes through point 18, is totally reflected by surface 9, and is output from terminal 3.

Further, the optical signal having the optical wavelength λ1 that has passed through the surface 10 by about 50% is totally reflected at the passing surface 8 having 192 points 15, and is output from the terminal 1. Here, the surface 82 and the surface 9 are surfaces that transmit 100% of the optical signals with the optical wavelengths λ2 to λ4, and the optical wavelengths λl
This is a surface that reflects 100% of the optical signal. Further, the surface 10 is a surface that transmits 50% and reflects 50% of the optical signal having the optical wavelength λ1.

The losses for the optical wavelengths λ2 to λ4 in the main line system (terminal 1 → terminal 3 or terminal 3 → terminal 1) are the loss between terminal 1 and optical element 4, the loss between terminal 3 and optical element 5, and the loss between optical element 4 and Optical element 5
It is the sum of the losses between (in this example, the losses including the optical waveguide 11). If we create a structure in which points 161 and 17 are directly connected,
The loss of the main line system is as low as 0.5 dB or less.

〔Effect of the invention〕

By using the optical element for optical wavelength multiplexing according to the present invention, it is possible to add an optical signal from the advanced station equipment to the main line system in an optical network using optical wavelength multiplexing technology, and the loss in the main line system is low. This has the effect of providing an optical multiplexing element.

[Brief explanation of drawings]

FIG. 1(a) is a functional diagram of the optical element according to the present invention.
FIG. 7(b) shows a structural diagram 7 of an optical element according to the present invention. 1-3...terminal, 4.5...optical element having a surface that totally reflects only the light wavelength λl and transmits other light wavelengths, 6.
. . . Element having a surface that splits incident light of optical wavelength λl on a one-to-one basis, 11 to 13 . . . Optical waveguide, 101 . . . Optical element (optical multiplexing element).

Claims (1)

[Claims] In an optical wavelength multiplexing optical element for inserting an optical signal with an optical wavelength λ1 different from any of the optical wavelengths into a transmission system of optical wavelength signals having optical wavelengths λ2 to λn (n: an integer of 2 or more), An optical signal having a wavelength λ1 is inputted, and the optical signal split by the first optical element that splits the optical signal and the optical signal split by the second optical element are respectively inputted, and the optical wavelength λ1 is totally reflected, and 2 that completely transmits light wavelengths λ2 to λn
second optical elements, the second terminals of each of the second optical elements are connected to each other, and each third terminal functions as an input/output terminal for insertion into the transmission system. An optical element for optical wavelength multiplexing, characterized in that: