O'Dowd, JA,Shi, K,Walsh, AJ,Bessler, VM,Smyth, F,Huynh, TN,Barry, LP,Ellis, AD

2012

January

Journal Of Optical Communications And Networking

Time Resolved Bit Error Rate Analysis of a Fast Switching Tunable Laser for Use in Optically Switched Networks

Validated

()

Packet switching Time resolved error detector Tunable laser Wavelength switching

4

77

81

We investigate the use of different direct detection modulation formats in a wavelength switched optical network. We find the minimum time it takes a tunable sampled grating distributed Bragg reflector laser to recover after switching from one wavelength channel to another for different modulation formats. The recovery time is investigated utilizing a field programmable gate array which operates as a time resolved bit error rate detector. The detector offers 93 ps resolution operating at 10.7 Gb/s and allows for all the data received to contribute to the measurement, allowing low bit error rates to be measured at high speed. The recovery times for 10.7 Gb/s non-return-to-zero on-off keyed modulation, 10.7 Gb/s differentially phase shift keyed signal and 21.4 Gb/s differentially quadrature phase shift keyed formats can be as low as 4 ns, 7 ns and 40 ns, respectively. The time resolved phase noise associated with laser settling is simultaneously measured for 21.4 Gb/s differentially quadrature phase shift keyed data and it shows that the phase noise coupled with frequency error is the primary limitation on transmitting immediately after a laser switching event.

DOI 10.1364/JOCN.4.000A77