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Optical Broadband Communications
Developed an interface card for a Free Space Optical (FSO) communications system based on Long Wave Infra-Red (LWIR) all-weather optical wireless (AOW) technology. Featuring multimode 1300nm fiber-optic or copper inputs and conversion of these inputs to a level (Emitter Coupled Logic [ECL] or Positive-referenced ECL [PECL]) compatible with a Quantum Cascade Laser (QCL) input; temperature sensing and control of laser temperature using thermoelectric coolers; control of laser power, bias, and modulation; conversion of outputs from a proprietary laser detector to multimode 1300nm fiber-optic or copper outputs; high-gain automatic gain control (AGC) amplification, limiting or direct connection of the detector signal; signal processing of the detector signal using adaptive clock and data recovery with a programmable continuous non-return-to-zero (NRZ) frequency coverage from 10 megabits per second to 2.7 Gigabits per second; continuous non-invasive bit error rate monitoring; communication protocol independent - gigabit Ethernet, Synchronous Optical Network (SONET) Optical Carrier (OC) OC-1 (51.84Mbps) /OC-3 (155.52Mbps) /OC-12 (622.08Mbps) /OC-48 (2.488Gbps); in-circuit programmable microcontroller; test mode for alignment; user control panel interface with buttons and 8-character dot matrix alphanumeric programmable display. Involved concept development, electronic circuit design, system engineering, block diagrams, schematics, printed circuit card (PCB) layout, firmware, cabling, harness, interconnects, test and integration.
Developed a Mobile Visibility Transmissometer (MVT) test instrument for measuring laser performance at three different wavelengths in the field. Designed a card to drive the lasers and a card to receive the laser transmission. The receiver used an innovative signal magnification circuit that measured small variations in signal strength. The system features uniform laser output over time using a feedback control circuit, thermoelectric cooler controls for laser cooling; heater controls for coping with outdoor environmental conditions; data collection via a programmable data logger; wireless data communication via cellular telephone. Involved concept development, electronic circuit design, system engineering, block diagrams, schematics, printed circuit card (PCB) layout, cabling, harness, interconnects, test and integration.
Investigated and evaluated new lasers, detectors, modulators and electronic devices; generated characteristic curves, eye diagrams, and researched the feasibility of electronic circuit designs to incorporate these new devices into an all-weather optical wireless (AOW) communications system. Designed electronic related portions of lab setups for research and demonstrations that required Bit Error Rate Testers (BERT), Digital Phosphor Oscilloscopes (DPOs), TEC (thermoelectric cooler) controllers, acousto-optic modulators and drivers, thermal imaging equipment, CO2 lasers, Quantum Cascade Lasers (QCL), Helium-Neon lasers, and other types of lasers, proprietary detectors, optical tables, various lenses, reflectors, beam splitters, and optical power meters. Set up and integrated electronic and optical equipment; directed lab personnel, performed optical alignments (visible and invisible), and verified performance with comparison to competitors equipment. Involved concept development, consulting, reverse engineering, redesign, electronic circuit design, system engineering, block diagrams, cabling, harness, interconnects, test and integration.
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