Wavelength monitoring of multi-channel DWDM-systems using a single temperature-tunable Fabry-Perot filter

Summary form only given. As the channel spacing is decreasing in optical DWDM-systems the need for accurate wavelength control of the transmitter increases. We have developed a device for wavelength monitoring of a multi-channel DWDM-system with one single temperature-tunable Fabry-Perot filter. The filter was fabricated by depositing two dielectric mirrors on both sides of a double-side polished silicon wafer. The reflectivity of the mirrors is 66% and the FSR of the filter is 110 GHz. The transmission of the filter can be tuned by controlling the temperature of the chip using an integrated heating resistor. The filter can be used as a wavelength reference by locking one of its transmission fringes to a stable reference, such as a molecular absorption line. When the filter transitivity as a function of wavelength is known, the close-by-lying wavelengths in a DWDM application can be monitored with an accuracy adequate for practical applications.