Agile Laser Transmitters and Receivers (ALTaR): Technologies for Flexible and Scalable Ultra-sensitive Free-space Optical Communications

May 12, 2022 @ 7:00 pm – 8:00 pm America/New York Timezone

Photonics Society

Agile Laser Transmitters and Receivers (ALTaR): Technologies for Flexible and Scalable Ultra-sensitive Free-space Optical Communications

Speaker: Dr. David O. Caplan, MIT Lincoln Laboratory

Although photon-counting optical receivers have the best known sensitivity in theory, in practice they are often constrained by inadequate bandwidth and background noise, which limits their utility for many applications. In this seminar, we will discuss agile laser transmitter and receiver (ALTaR) technologies that can address these limitations.

On the transmitter side, time- and frequency-windowed directly modulated lasers can efficiently generate a variety of wavelength division multiplexed (WDM) optical waveforms with good fidelity. On the receiver side, new low-loss optical filtering technologies allows existing photon-counting detector technologies to support high-speed and high-sensitivity photon-counting reception – while eliminating existing noise, bandwidth, and other limitations. Efficient narrow-band WDM optical filtering can provide nearly matched optical filtering, reducing the impact of background noise while providing efficient access to many THz of available optical spectrum. Combining this with time- and frequency-based hybrid-orthogonal modulation enables robust and extensible high-sensitivity performance in the presence of background – at rates that can scale to many Gbits/s and beyond. An overview of ALTaR technologies will be presented along with their impact on a variety of space-based lasercom applications.


Dr. David Caplan is a Senior Staff member in the Optical and Quantum Communication Technology Group at MIT Lincoln Laboratory. His research has focused on high-sensitivity laser communication systems and related technologies, with an emphasis on photon- and power-efficient transmitter and receiver design, with recent emphasis on agile multi-rate and multi-format transceiver technologies to support future free-space optical network architectures.

During his tenure at MIT Lincoln Laboratory, David has made key contributions to several ground-breaking space-laser communications demonstrations.  He led the development of transmitter systems for the 2001 GeoLITE mission, the world’s first successful high-rate space-based laser communications system.  His pioneering work on high-sensitivity multi-rate optical transceivers has been incorporated into NASA’s near-Earth and deep-space interplanetary laser communication initiatives including the Mars and subsequent Lunar Laser Comm. Demo (LLCD), the Laser Comm. Relay Demo (LCRD) satellite which launched in 2021, and the ongoing Orion Artemis II Optical Comm. (O2O) program.  Among other noteworthy capabilities, O2O will provide operational lasercom to future manned missions to the Moon, using modulation techniques, waveforms, and transceivers based on his designs that increase state-of-the-art uplink capacity by more than 3 orders-of-magnitude.  His contributions in the field were recognized with the MIT Lincoln Laboratory Technical Excellence Award and a recent R&D100 Award for Multi-rate DPSK as one of the 100 most technically significant products of the year.

David has also been active in both OPTICA (OSA) and IEEE, serving two terms as Associate Editor for the Journal of Lightwave Technology and recently joined the editorial team for IEEE Access.  He was a guest editor for the IEEE Journal of Selected Topics in Quantum Electronics (JSTQE) and Journal of Optical Communication Networks (JOCN), has served as a member of the OSA Conference on Lasers and Electro-Optics (CLEO) and IEEE Photonics Society technical program committees, chaired the CLEO Lightwave Communications and Optical Networks Technology committee, and served as General Chair of the Optica-OSA Advanced Photonics Congress Photonics Networks Conference.  He is a senior member of IEEE and an OPTICA fellow.

This meeting will be online only.

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