| 摘要 |
PROBLEM TO BE SOLVED: To highly accurately confirm an operation of device function.SOLUTION: An optical preamplifier 11 amplifies input light. An optical postamplifier 12 amplifies output light from the optical preamplifier 11. A loopback processing section 13 executes loopback processing to loop the output light from the optical postamplifier 12 back to the optical preamplifier 11. The loopback processing section 13 generates natural emission light 1 from the optical postamplifier 12 in loopback processing, causes the optical preamplifier 11 to amplify the natural emission light 1, and causes the optical preamplifier 11 to output a natural emission light 1a having wavelength characteristics of flat optical power in the wavelength band of signal light. |
