A temperature compensation technique is proposed and demonstrated for highly accurate control of the transmission wavelength of wavelength-tunable optical bandpass filters. The technique calculates wavelength error, which is caused by transient variations of the operating temperature of filter modules, by use of the theory of thermal conduction and controls the filter with an appropriate offset according to the calculated value to maintain a constant transmission wavelength. A disk-shaped wavelength-tunable filter based on a mechanical tuning mechanism is demonstrated to confirm the validity of the technique. For the filter, the transmission wavelength is controlled to an accuracy of 0.01 nm against drastic temperature variations whose maximal change rate reaches 2.5 °C∕min in the range of 20-50 °C. A filter controlled with this technique has the potential to provide high-performance channel selectors for wavelength-division-multiplex-based photonic networks, and its feasibility is confirmed by transmission experiments at 2.5 Gbit/s.
© 2004 Optical Society of AmericaPDF Article