To induce a targeted non-linear optical effect by a high-peak-power light by using a light pulse from a semiconductor laser without using a light pulse from a large, high-average-power solid laser such as titanium sapphire laser. A semiconductor laser pulse beam with a wavelength of 1550 nm (for example, repeatability of 1 MHz) from a semiconductor laser (laser diode: LD) is efficiently amplified in two stages, front-end and main EDFAs. An optical filter removes a spontaneous emission light component that is noise. An optical filter picks up, from the amplified pulse beam, second harmonic light pulse produced by the non-linearity of an optical device (frequency polarization inversion Mg-added LiNbO.sub.3:PPMgLN) to produce a super-continuum light in a 800 nm wavelength region from a photonic crystal fiber (PCF).