Optical fiber interference wavelength/frequency detection apparatus which eliminates a movable element

摘要: The invention provides an optical wavelength/frequency detection apparatus for detecting a wavelength of frequency laser source, which is improved in that it eliminates movable element to achieve high degree long term reliability and can detect or light with accuracy resolution while small size. comprises pair fibers individually propagating two outputs measurement splitting coupler, driver varying the relative difference between path lengths beams propagated fibers, receiver receiving interference from combining counter counting number pulses received by receiver. Measurement information reference are processed comparison calculation processing calculate light.