All-Optical NRZ-to-Inverted-RZ Converter with Extinction Ratio Enhancement Using a Modified Terahertz Optical Asymmetric Demultiplexer

SUMMARY To enhance the extinction ratio (ER) of NRZto-inverted-RZ converter based on cross-gain compression of a semiconductor optical amplier (SOA), a modied terahertz optical asymmetric demultiplexer (TOAD) is cascaded. ER is improved from 1.6{6.7 dB to 5.4{14.5 dB, depending on the intensity of input optical NRZ signal. The proposed NRZ-to-inverted-RZ converter enhances and regulates ER to a high value (14.5 dB) for very wide optical NRZ signal intensity range.