{'fraction_non_alphanumeric': 0.037484885126964934, 'fraction_numerical': 0.018137847642079808, 'mean_word_length': 4.447368421052632, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Broad-band wavelength up-conversion of picosecond pulses via four-wave mixing in a quantum-dash waveguide

Wavelength up-conversion of 1.6-ps pulses is achieved through four-wave mixing (FWM) in an InAs-InP quantum-dash ridge waveguide laser operating at 1587 nm. The up-conversion efficiency is measured as a function of injection current, for pump-probe detunings in the range 1.8-3.8 THz. The efficiency is found to increase with current up to a point of saturation. The gain at the conjugate wavelength is found to enhance the efficiency. For a detuning of 1.8 THz, an efficiency of -17.6 dB is obtained; this is similar to or higher than reported efficiencies for FWM with continuous-wave signals in quantum dots and dashes, at similar detunings. Further improvement may be obtained through optimization of the pump power.