| 摘要 |
PROBLEM TO BE SOLVED: To eliminate a tracking error generated during bias control of a laser diode.SOLUTION: An optical module comprises a laser diode, an APC circuit which controls a bias current by monitoring the rear light output of the laser diode, and a waveguide type multiplexer which outputs the tracking error (TE) of front light output, due to change of temperature conditions, while correcting. The function as a waveguide type multiplexer is obtained by presetting the transmission center wavelength of the waveguide type multiplexer to a wavelength (λ') in the high temperature range (A). Even if the loss due to TE increases in the high temperature range (B), or the loss decreases in the low temperature range (B), variation of loss is corrected by the spectral characteristics of the waveguide type multiplexer, and the optical output is stabilized (C). |
