Programmable optical waveform reshaping on a picosecond timescale

Abstract

We experimentally demonstrate the temporal reshaping of optical waveforms in the telecom wavelength band using the principle of quantum frequency conversion. The reshaped optical pulses do not undergo any wavelength translation. The interaction takes place in a nonlinear χ⁽²⁾ waveguide using an appropriately designed pump pulse programmed via an optical waveform generator. We show the reshaping of a single-peak pulse into a double-peak pulse and vice versa. We also show that exponentially decaying pulses can be reshaped into a near Gaussian shape, and vice versa, which is a useful functionality for quantum communications.

Tailoring nonlinear processes for quantum optics with pulsed temporal-mode encodings

“…Applying their waveform generation and numerical optimisation to this situation, they were able to demonstrate efficiencies above 75% for a four-dimensional Hermite-Gaussian alphabet with separabilities above 65% and as high as 87% for picosecondscale Gaussian pulses [98]. These results have been extended to novel mode-selective pulse-shaping schemes based on over-conversion in SFG [107] and demonstrations of mode-selective upconversion with efficiencies and selectivities high enough to outperform time-frequency filtering for signal isolation [108].…”

Time reversal of arbitrary photonic temporal modes via nonlinear optical frequency conversion

“…In addition to noiseless waveform manipulation, in quantum networks there is also a need for noiseless frequency conversion (FC), which together with pulse shaping can enable complete temporal and spectral 'impedance' matching between quantum emitters and absorbers that are not identical (for example, a rubidium vapor and a GaAs quantum dot), having different carrier frequencies and decay times [18][19][20][21]. Such frequency conversion has been demonstrated for single photons using nonlinear three-wave mixing to implement sumfrequency generation (SFG) [22] while maintaining single-photon number statistics [23] and even quantum entanglement [24] with other physical systems.…”

“…This prevents the technique being used to implement quantum logic operations in a state space of temporal shapes (modes)-an important capability in quantum information science [17] In addition to noiseless waveform manipulation, in quantum networks there is also a need for noiseless frequency conversion (FC), which together with pulse shaping can enable complete temporal and spectral "impedance" matching between quantum emitters and absorbers that are not identical (for example, a rubidium vapor and a GaAs quantum dot), having different carrier frequencies and decay times. [18,19,20,21] Such frequency conversion has been demonstrated for single photons using nonlinear three-wave mixing to implement sum-frequency generation [22] while maintaining single-photon number statistics [23] and even quantum entanglement [24] with other physical systems. For FC between frequencies separated by smaller differences than can be accommodated by sum-or difference-frequency generation, four-wave mixing has been demonstrated for converting the frequency of single photons.…”

Pulse shaping using dispersion-engineered difference frequency generation

“…For two-dimensional states, reshaping (i.e. modal rotation) has been explored [17]. However, an independent TM multiplexing device capable or arbitrary TM shaping and reshaping of higher order modes such as the Quantum Pulse Shaper (QPS) described in Ref.…”