Presenting at Space Technology Showcase
PhD student Jack Postlewaite will present an update on work related to the Green Machine receiver at the UMD Space Technology Showcase
In the photon-starved depths of space, where data demands outstrip traditional RF links, a breakthrough emerges from the University of Maryland: a hardware-efficient super-additive joint detection optical receiver. Dubbed the Green Machine, this innovation pairs BPSK Hadamard modulation with a reconfigurable optical joint-detection receiver (O-JDR) to shatter classical limits. Achieving 3.15 bits per photon—surpassing the 2.88-bit plateau of symbol-by-symbol detection—it enables higher bandwidth, lower SWaP, and unregulated spectrum for Lunar and Martian missions. Led by Jack Postlewaite, Chaohan Cui, and collaborators from UMD, NASA Goddard, and UT Austin, the work demonstrates super-additivity via structured unitary transformations, paving the way for entanglement-free nonlocality in optical links.
The experiment unfolds on a fiber-optic platform: a 1550nm CW laser undergoes BPSK modulation into Hadamard codewords, attenuated to mimic deep-space loss, then processed through multi-stage interferometers with switchable delays and SNSPDs. Transition probability matrices from time-tagged photons reveal the receiver’s edge—GM4 outperforms PPM direct detection even under realistic losses. Reconfigurability via Sine-Cosine Fractal decomposition allows scalable unitaries without fixed stages, trading minor latency for adaptability. Results plot PIE against mean photon number, closing the gap to Holevo capacity and highlighting potential for quantum-enhanced variants.
This poster debuts at the inaugural UMD ASTRA Space Technology Showcase on October 15, 2025, from 1-3 PM in A. James Clark Hall’s Forum 1101. Hosted by UMD’s Center for Advanced Space Science and Technology Research, the event spotlights cross-campus innovations—from orbital debris detection to lunar rovers—fostering academia-industry-government ties. Keynote by Dr. Nancy Chabot of JHU APL details the DART mission’s asteroid deflection triumph, inspiring planetary defense parallels to optical comms resilience. Free with refreshments; register via astra.umd.edu to witness Maryland’s space tech vanguard.