Detecting aging of optical components

摘要

The invention in accordance with one aspect is a method of determining aging of a light emitting device (11) which is capable of selectively emitting light having different wavelengths corresponding to different channels for light transmission as a function of tuning current supplied to the device. A tuning current is applied to the device (11), which results in a wavelength corresponding to a desired channel. The slope of a curve, which is light power from the device (11) as a function of tuning current, is determined by dithering about the applied tuning current. The determined slope is compared with a prior determined value in order to detect any change from the prior value. The voltage derived from a light signal passing through an optical filter (16) can also be measured and compared to a prior value. These values may be used to determine aging of the device (11) and the filter (16).