Experimental application of LD switch modules to 256 Mbit/s optical time switching

The letter proposes an optical time switch using LD switch modules and serial delay lines, and reports on its performance for a 256 Mbit/s 4 × 4 switching system. It can be constructed with fewer delay lines, and needs neither polarisers nor temperature control. Its total insertion loss is 24.8 dB with a loss margin of 4.0 dB.