Common Light Source for Optical Testing

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Published:
01/26/2010
Last Updated:
01/26/2010
Patent Number:
US 6,324,333 B1
A method and apparatus for testing a plurality of optical circuits provides a single broadband light source and means for splitting the light produced by the broadband light source in order to produce a plurality of light beams each of which is directed to a selected one of the plurality of optical circuits.

Patent Overview

Background of the Invention
This invention relates to apparatus for testing an optical circuit. More particularly, the invention relates to a light source for testing an optical circuit. Light is used to test integrated optic devices.
An integrated optic chip (IOC) is made of an electro-optic material whose index of refraction increases or decreases depending on the direction of electric field applied to it. IOC’s are analogous to integrated circuits (IC’s) utilized in semiconductor technology. The signal processing in an IC is totally electric whereas in an IOC it is both optical and electrical. The term “integrated” in “integrated optic chip” implies that the chip has both electrical and optical parts. One or more external electrical signal(s) is applied to one or more electrodes formed on and IOC and the electrical signals change the index of refraction of one or more waveguides adjacent to the electrodes. Changing the index of refraction of a waveguide produces a concomitant change in the intensity and/or phase of light passing through the waveguide. An IOC device is a device which includes one or more IOC’s.
During the testing of multiple IOC devices, it is common practice to provide a separate laser light source for each IOC device. This procedure is labor intensive, is costly, and can also make it difficult to readily determine when a particular laser is not operating properly.