PICULS: PHOTONIC INTEGRATED CIRCUITS FOR ULTRA-LOW SIZE WEIGHT AND POWER PHOTONIC INTEGRATED CIRCUIT (PIC) TECHNOLOGY ENABLES ULTRA-LOW SIZE WEIGHT AND POWER (SWAP) WHILE ALSO EFFICIENTLY UTILIZING THE COMMUNICATION BANDWIDTH AFFORDED BY OPTICS. WE PROPOSE TO DESIGN FABRICATE AND TEST SPACE OPTICAL COMMUNICATION PICS. IN PARTICULAR WE AIM TO BUILD A COHERENT TRANSCEIVER PIC SUPPORTING USER-SELECTABLE DATA RATES FROM 10 MBPS TO 500 GBPS. TO ACCOMPLISH THIS OBJECTIVE WE WILL DEVELOP A SILICON INTERPOSER CONTAINING (1) A SILICON PHOTONIC (SIPH) PIC WITH RECEIVER ELEMENTS AND (2) A HYBRIDINTEGRATED INDIUM PHOSPHIDE (INP) PIC CONTAINING TRANSMITTER COMPONENTS AND LOCAL OSCILLATOR (LO) LASERS FOR THE RECEIVER. THE INP PIC WILL BE INTEGRATED ONTO THE SILICON INTERPOSER PIC WITH A 3D INTEGRATION TECHNIQUE THAT WE RECENTLY DEMONSTRATED. WE HAVE DEVELOPED PIECES OF THIS PROPOSED PIC TRANSCEIVER IN OTHER WORK BUT HAVE NEVER MERGED SUCH ELEMENTS IN A SINGLE IMPLEMENTATION. HERE WE ALSO PROPOSE THE INTEGRATION OF A HIGH-POWER SEMICONDUCTOR OPTICAL AMPLIFIER (SOA) TECHNOLOGY TO ACHIEVE THE OPTICAL OUTPUT POWERS REQUIRED FOR SPACE OPTICAL COMMUNICATION. IN DEVELOPING THE SILICON INTERPOSER TRANSCEIVER WE WILL BRING TOGETHER BEST-IN-CLASS TECHNOLOGIES (SIPH AND INP) ON A COMMON CMOS-COMPATIBLE PLATFORM. INP IS THE IDEAL CHOICE FOR THE 1550-NM TRANSMIT LASERS HIGHEFFICIENCY MODULATORS HIGH-POWER SOA AND LO LASERS. AND SIPH IS THE IDEAL CHOICE FOR A COMPACT DEMULTIPLEXER OPTICAL HYBRID AND BALANCED PHOTODETECTORS. THE LO LASERS WILL COUPLE LIGHT FROM THE INP PIC TO THE SIPH PIC WITH OUR 3D INTEGRATION TECHNOLOGY. OUR RESEARCH GROUP HAS PIONEERED PICS ON A NUMBER OF MATERIALS PLATFORMS AND WE WORK EXTENSIVELY WITH PHOTONICS FOUNDRIES ACROSS THE GLOBE. WE ALSO UTILIZE STATE-OF-THE-ART NANOFABRICATION CAPABILITIES IN HOUSE. WE ARE A MEMBER OF ONE OF THE THREE PROPOSING TEAMS THAT WERE SELECTED TO SUBMIT A FULL PROPOSAL TO THE INTEGRATED PHOTONICS INSTITUTE FOR MANUFACTURING INNOVATION (IP-IMI) COMPETITION. AND WE ARE CURRENTLY A PERFORMER ON A NASA EARLY CAREER FACULTY SPACE TECHNOLOGY RESEARCH GRANT WHERE WE ARE DEVELOPING LOW SWAP LASERS TRANSMITTERS FOR DEEP SPACE COMMUNICATIONS. HERE WE WILL BUILD ON OUR EXISTING EXPERTISE TO REALIZE A FULLY-FUNCTIONAL PIC TRANSCEIVER FOR SPACE OPTICAL COMMUNICATIONS. WE WILL DEMONSTRATE A SILICON INTERPOSER TECHNOLOGY TO MERGE MONOLITHIC SIPH COMPONENTS AND HYBRID INTEGRATED INP COMPONENTS. THE INTERPOSER TECHNOLOGY WOULD ALSO BE CAPABLE OF HOSTING HYBRID INTEGRATED ELECTRONICS IN FUTURE IMPLEMENTATIONS. WE WILL UTILIZE BOTH IN-HOUSE FABRICATION AND FOUNDRY PROCESSES AND A HOST OF DESIGN SIMULATION AND LAYOUT TOOLS. IN DOING SO WE WILL DEMONSTRATE THE USE AND ADVANCEMENT OF A PHOTONICS MANUFACTURING ECOSYSTEM FOR SPACE OPTICAL COMMUNICATIONS PICS. THIS PROPOSED WORK WILL MAKE SPACE SCIENCE AND EXPLORATION MORE EFFECTIVE AFFORDABLE AND SUSTAINABLE BY ENABLING LOW COST AND LOW SWAP TECHNOLOGIES FOR COMMUNICATIONS WHILE FREEING UP RESOURCES FOR OTHER ONBOARD SYSTEMS. THE PIC TECHNOLOGY WILL ALSO BETTER UTILIZE THE HIGH BANDWIDTH AFFORDED BY OPTICS AND SCALE READILY TO HIGHER DATA RATES.