| 摘要 |
A wavelength conversion device including a nonlinear medium having quantum dots uses a tunable laser as an excitation light source of optical four wave mixing, and performs wavelength conversion for a wide bandwidth signal light with optical four wave mixing. In a wavelength conversion system (40) any one of the signal light having a wavelength of »1, »2, ..., »n is supplied to the wavelength conversion system (40) which includes an optical amplifier (41) for amplifying the signal light with an amplification factor ±, a tunable laser (42), and an optical amplifier (43) for amplifying an output laser light from the tunable laser (42) with an amplification factor ². The light amplified in the optical amplifiers (41, 42) is coupled in an optical coupler (45) and supplied via an optical circulator (46) and a polarization beam splitter (47) to the quantum dot optical amplifier (20). A 1/2 wavelength plate (48) is inserted in the optical port of the polarization beam splitter (48) from which the TM mode light is extracted and converted to a TE mode light. |
