PURPOSE: To take out a single optical pulse output by making light with an optional polarizing state incident upon a light incident end of an optical fiber and obtaining a non-linear optical output from one projection end of a polarization selecting type directional coupler.
CONSTITUTION: Linearly polarized input light is made incident upon the light incident end 4a of the low double refractive optical fiber 4 so that the polarizing face is parallel with the (y) axis of the optical fiber 4. In the optical fiber 4, double refraction (optical Kerr effect) generated by the incident light competes with inherent double refraction included in the optical fiber 4 and the non-linear conversion of optical power from a y-axis transmission mode to an x-axis transmission mode is generated. The converted x-axis transmission mode Ex and the residual y-axis transmission mode Ey are made incident upon the incident end 1a of the polarization selecting type directional coupler 3 and separated by the coupler 3 and these modes Ex, Ey are outputted respectively from outgoing ends 2b, 1b. Consequently, a single optical pulse having pulse width narrower than that of an input optical pulse can be outputted.
NAKAZAWA MASATAKA
AOMI YOSHIYUKI
Next Patent: ORGANIC NONLINEAR TYPE OPTICAL MATERIAL