We report on the design, development, and testing of the high-power Laser Transmitter Assembly (LTA) supporting the Deep Space Optical Communications (DSOC) demonstration hosted on the Psyche Discovery class mission, due to launch in 2022. The DSOC project, under development by NASA’s Jet Propulsion Laboratory, will test space-to-ground high-bandwidth laser communications while en route to the Psyche-16 asteroid in the main asteroid belt, in what will be the longest range high rate optical communications link in history. The LTA is based on a master-oscillator power-amplifier optical architecture, using highly-efficient cladding-pumped amplification. The transmitter is designed to deliver average optical output powers <4 W at 1550 nm for low power consumption data links at <100 Mbps. The output signal operates across multiple pulse-position modulation (PPM) orders and pulse-widths to optimize the space-to-ground link. The architecture is designed for high-reliability and radiation hardness, and features hardware interlocks and secondary signal/pumping paths to reduce single points of failure. We also detail the effective management of optical nonlinearities which could damage the LTA or impact the communications link. These include the suppression of stimulated Brillouin scattering, self-phase modulation, and pulseto- pulse energy variation (PEV), which arises from the gain dynamics of the power amplifier, and will manifest when the LTA is configured for large pulse energies and long inter-pulse delays. The LTA also incorporates hardware and software controls to enable autonomous operation, including closed-loop control of intra-stage and output power levels, modulator bias control, and detailed reporting of LTA status through telemetry.

We propose and demonstrate all-optical method for generating advanced modulation formats with high-spectral efficiency. The proposed method is based on all-optical format conversion using photonic-integrated semiconductor optical amplifier-Mach-Zehnder interferometers. It enables application of advanced modulation formats at data rates not directly accessible using electronic means only. We demonstrate generation of single-polarization 86.4-Gb/s binary phase-shift keying and 173-Gb/s quadrature phase-shift keying optical signals.

We propose a novel method of all-optical OR operation using semiconductor optical amplifier Mach-Zehnder interferometers. We demonstrate all-optical OR operation at 42.8 Gb/s using a hybrid photonic integrated device.

We demonstrate a method of minimizing the wavelength sensitivity of the all-optical bit-pattern recognition relying on a passive optical correlator. We accomplish all-optical 40-Gb/s, 8-bit pattern recognition with much reduced wavelength sensitivity by combining a wavelength converter front-end and a passive optical correlator.

We report generation of high spectral-efficiency modulation formats at 86.4 Gbaud/s by all-optical format conversion using a device integrating semiconductor optical amplifies. We demonstrate generation of 173 Gbits/s QPSK signals and 86.4 Gbits/s Binary-PSK signals.

We propose a method for increased-speed all-optical XOR operation using semiconductor optical amplifiers. We demonstrate XOR and XNOR operations at 86.4 Gb/s using a pair of photonic-integrated semiconductor optical amplifier Mach-Zehnder interferometers.

We report all-optical detection of 32-bit patterns embedded in 40-Gb/s phase-shift keyed data. The bit-pattern recognition is achieved using matched filtering implemented with a reconfigurable silica waveguide tapped delay-line filter.

We present a compact reconfigurable 8-bit optical matching filter fabricated using 4% delta high-index-contrast silica-on-silicon waveguides. We demonstrate its working by successfully correlating 8-bit binary phase-shift keyed patterns.

We present experimental investigations of the dynamical properties of semiconductor optical amplifiers (SOAs) and their impacts in all-optical signal processing using SOAs. We introduce ultrafast optical signal characterization techniques to fully characterize the gain and phase dynamics of SOAs. We elucidate a consequence of the slow carrier recovery as pattern-dependent phase fluctuation in wavelength conversion of ON-OFF-keyed signals. We also analyze the conversion of the phase fluctuation into amplitude fluctuation limiting the performance of all-optical XOR operation. Finally, the performance of all-optical wavelength conversion of differential phase-shift-keyed signals is presented with emphasis on regeneration of the phase information.

We demonstrate all-optical recognition of byte patterns embedded in phase-shift-keyed data streaming at 40 Gb/s. We use matched filtering to generate an autocorrelation pulse indicating the pattern matching. Matched filtering is implemented using a reconfigurable silica planar-lightwave-circuit optical delay-line filter. We show excellent discrimination against spurious patterns consistent with the theoretical predictions.

All optical Boolean logic devices have the potential to perform many important operations in future all-optical, high speed communications networks. Some advantageous uses may be in bit pattern matching [1], pseudo random number generation [2], optical label swapping [3], and encryption [2]. Performing such operations optically is desirable in the effort to overcome the speed and power consumption limitations inherent in electronic operations. All of these examples rely on Boolean exclusive-OR (XOR) functionality, in which output is nonzero if and only if one of two input signals is a logical 1 and the other is a logical 0