WAVELENGTH CONVERTER AND WAVELENGTH CONVERTING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain the wavelength converting device which does not output an inputted wavelength component from itself by outputting a band-limited wavelength by an optical filter which limits the band of amplified light and has cyclic transmission characteristics on a wavelength axis. SOLUTION: One of waves differing in wavelength is inputted from an input terminal 1. This light signal has its light intensity modulated. A laser light source 3 of single-mode oscillation outputs the wavelength of a conversion destination. After multiplexing by a multiplexer 2, the gain of a semiconductor laser type optical amplifier 4 varies through light-intensity modulation to impose on an unmodulated signal such modulation that the mark and space of an input modulated signal shown by a modulated signal after wavelength conversion are reversed. The transmission characteristics of an optical filter 5 following the output of a semiconductor laser type optical amplifier 4 allow the transmission of only the wavelength component after conversion. The wavelength of the conversion destination can be selected without varying the transmission frequency because of the arranged optical filter 5 having the cyclic transmission characteristics.