| 摘要 |
A system and method of compensating for the thermal dependence of fiber optic devices, such as Bragg gratings, are described. Fiber optic devices such as Bragg filters are subject to change as a function of temperature. If the device contains a grating which is written to perform a function at a specific central wavelength, a slight increase in length of the device and hence an increase in the grating spacing due to an increase in temperature will change the central wavelength. The present invention provides a two-part substrate structure with each part having a different coefficient of thermal expansion. The fiber optic device is attached under tension to one part of the substrate that has, for example, a low coefficient of thermal expansion. This part has a channel on the side opposite to the fiber optic device and a second part of the substrate structure is held within the channel. The second part has a high coefficient of thermal expansion. Thus, when the temperature increases the first part of the substrate is forced to bend upwards which changes the stress on the fiber optic device such that the operating wavelength is compensated by an amount equal to the thermally induced change.
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