Optical packet switching system

An optical packet switching system comprising:

• an optical packet generator configured to generate an optical packet signal;
• an optical packet switching unit, provided with an optical switch, configured to switch a route of an inputted optical packet signal by controlling on/off of the optical switch;
• and an optical signal-to-noise ratio measuring unit configured to measure an optical signal-to-noise ratio of the optical packet signal outputted from the optical packet switching unit, wherein, when switching the route of the optical packet signal, the optical packet switching unit outputs an optical packet signal with optical noise by keeping the optical switch on for a time length that is longer than the time width of the packet signal, and wherein the optical signal-to-noise ratio measuring unit measures an optical signal power and an optical noise power, respectively, in the optical packet signal with optical noise and measures the optical signal-to-noise ratio by calculating the ratio between the optical signal power and the optical noise power.