Experimental demonstration of optical Nyquist generation of 32-Gbaud QPSK using a comb-based tunable optical tapped-delay-line FIR filter

We experimentally demonstrate tunable optical Nyquist generation of 32Gbaud QPSK signals using optical tapped-delay line. Optical Nyquist spectra for different number of taps are shown, and 20% EVM and 2.8 dB OSNR penalty at BER of 1e-3 are measured.