METHOD FOR DETECTING WAVELENGTH AND CIRCUIT FOR DETECTING WAVELENGTH AND APPARATUS EMPLOYING THEM

摘要

An apparatus arranged to multiplex an optical signal obtained by modulating a reference light having a periodically varying wavelength with specified pattern data and an optical signal being detected before converting them into an electrical signal, to detect the error rate of the electrical signal with respect to the specified pattern data, and to detect the wavelength components included in the optical signal being detected from the wavelength of the reference light at such a timing as the error rate exceeds a specified value. With such an arrangement, a plurality of wavelengths included in the optical signal being detected can be detected collectively and optical components including prisms can be omitted while reducing the size and the cost.