JP2000147277A - Optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to maintain a waveguide chip at prescribed temperature without increasing electric power consumption even if outdoor temperature rises high by covering the endothermic side periphery of at least a temperature compensating means in a package with thermally insulating material. SOLUTION: This optical module is constituted by providing the waveguide chip 7 with the temperature compensating means 8, such as a Peltier element, via a soaking plate 9, housing this chip a package 11 and leading the optical fiber 10 connected to the waveguide chip 7 to the outside of the package 11. In such a case, the thermally insulating material 12 is packed into the package 11. Foamable silicone or foamed polyurethane is usable as the thermally insulating material 12. The heat flowing into the package 11 may be prevented from arriving at the temperature compensating means 8 by packing the thermally insulating material 12 into the package 11 in the manner described above. The waveguide chip 7 may thus be maintained at the prescribed temperature without increasing the electric power consumption of the temperature compensating means 8. The occurrence of dew condensation on the endothermic side 8a of the temperature compensating means 8 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical module of an array waveguide diffraction grating type used for optical wavelength division multiplexing communication.

[0002]

2. Description of the Related Art In recent years, in optical communications, research and development on optical frequency multiplexing communications have been actively pursued in order to dramatically increase the transmission capacity. In order to increase the transmission capacity, an optical module capable of multiplexing and demultiplexing light having a small wavelength interval is required.
As such an optical module, for example, an optical module using an optical multiplexer / demultiplexer using an arrayed waveguide diffraction grating is known.

This optical module is, for example, shown in FIG.
As shown in (b), on a substrate 1 made of silicon, quartz, sapphire, or the like, an array waveguide 3 made up of a plurality of channel waveguides 2 having slightly different optical path lengths between adjacent waveguides; An optical multiplexer / demultiplexer including a waveguide chip 7 in which a waveguide layer 6 having first and second slab waveguides 4 and 5 is stacked is used. In this waveguide chip 7, when light of multiple wavelengths is incident on the array waveguide 3 via the first slab waveguide 4, diffracted light corresponding to the optical path length difference is transmitted to the second slab waveguide. Emitted into the wave path 5,
Light of multiple wavelengths is split. On the other hand, conversely, the second
When various lights having different wavelengths are incident on the array waveguide 3 via the slab waveguide 5, the lights are multiplexed corresponding to the optical path length difference, and the first slab waveguide 4
Is emitted to.

In an optical module using the waveguide chip 7, light is multiplexed / demultiplexed by an array waveguide 3 including a plurality of channel waveguides 2 having different optical path lengths. For this reason, in the optical module, it is necessary to keep the temperature of the waveguide chip 7 constant so that the effective optical path length difference of the channel waveguide 2 is not affected by the temperature change.

Therefore, in the above optical module,
As shown in FIG. 3, a temperature compensating means 8 such as a Peltier element for cooling the waveguide chip 7 is provided, and a good thermal conductivity such as metal or plastic is provided between the waveguide chip 7 and the temperature compensating means 8. A heat equalizing plate 9 made of a suitable material and having a temperature measuring means (not shown) such as a thermistor is disposed so as to be in close contact. A silicon paste, an adhesive or the like is interposed between the heat equalizing plate 9 and the waveguide chip 7 to improve heat transfer. In addition, 10 is an optical fiber,
11 is a package. Then, the temperature compensating means 8 is feedback-controlled by the control means based on the temperature measured by the temperature measuring means, and the temperature of the waveguide chip 7 is controlled to be constant.

[0006]

However, when the temperature outside the package 11 becomes high, heat flows into the package 11 and the power consumption of the temperature compensating means 8 for controlling the temperature of the waveguide chip 7 increases. However, in some cases, there is a problem that the temperature control does not work. Further, depending on the atmosphere in the package 11, dew condensation occurs on the heat absorbing side 8a of the temperature compensating means 8, and the heat capacity of the heat absorbing side 8a increases, so that the power consumption of the temperature compensating means 8 increases. When dew condensation occurs between the sides 8b, there is a problem that a short circuit occurs thermally and electrically, and the temperature control does not work.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a waveguide chip having an optical waveguide on its surface, and a temperature compensation means for maintaining the waveguide chip at a predetermined temperature. Is housed in a package, wherein at least the heat absorbing side periphery of the temperature compensating means in the package is covered with a heat insulating material.

According to the present invention, since the periphery of the heat absorbing side of the temperature compensating means is covered with the heat insulating material, even if heat flows into the package from outside, the heat absorbing side of the temperature compensating means is exposed to a high temperature atmosphere. Therefore, the waveguide chip can be maintained at a predetermined temperature without increasing power consumption. In addition, since the heat absorbing side of the temperature compensating means does not directly contact the atmosphere and can prevent dew condensation from occurring, it is possible to prevent an increase in power consumption and a thermal or electrical short circuit.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of an embodiment of the optical module according to the present invention. FIG. 1 shows FIG.
The same parts as those described above are indicated by the same reference numerals. In this embodiment, a package in which a temperature compensating means 8 such as a Peltier element is provided on a waveguide chip 7 via a heat equalizing plate 9 is housed in a package 11, and an optical fiber 10 connected to the waveguide chip 7 is packaged. 11 is drawn out.

The present embodiment is different from the conventional example in that a heat insulating material 12 is filled in a package 11. As the heat insulating material 12, foamable silicone (for example, SE1900 manufactured by Dow Corning Toray Silicone Co., Ltd.)
Alternatively, X-31 @ 1247 manufactured by Shin-Etsu Silicone Co., Ltd. or foamed polyurethane (for example, high-span foam manufactured by Cemedine) can be used.

As described above, the heat insulating material 1 is contained in the package 11.
2 prevents the heat flowing into the package 11 from reaching the temperature compensating means 8,
The waveguide chip 7 can be maintained at a predetermined temperature without increasing power consumption. Further, the temperature compensating means 8
Since the heat absorbing side 8a does not come into direct contact with the atmosphere, no dew condensation occurs on the heat absorbing side 8a.
Electrical short circuits can be prevented.

In the above embodiment, the package 11
Although the entire space inside is filled with the heat insulating material 12, the heat insulating material 12 does not necessarily need to be filled entirely. The heat insulating material 12 may cover at least the vicinity of the heat absorbing side 8a of the temperature compensating means 8.

[0013]

As described above, according to the present invention, the waveguide chip can be maintained at a predetermined temperature without increasing power consumption even when the outside air temperature increases, and the temperature compensation means can be used. There is an excellent effect that condensation can be prevented from occurring on the heat absorbing side.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of an optical module according to the present invention.

FIGS. 2A and 2B are a plan view and a side view of a waveguide chip, respectively.

FIG. 3 is a sectional view of a conventional optical module.

[Explanation of symbols]

 REFERENCE SIGNS LIST 7 Waveguide chip 8 Temperature compensating means 8 a Heat absorbing side 8 b Heat generating side 9 Heat equalizing plate 10 Optical fiber 11 Package 12 Heat insulating material

Claims (1)

[Claims] 1. An optical module comprising: a waveguide chip having an optical waveguide on its surface; and a temperature compensating means for maintaining the waveguide chip at a predetermined temperature. An optical module characterized in that the periphery of the heat absorbing side is covered with a heat insulating material.