We describe the development of a hardware turbo decoder on a field-programmable gate array for high-speed free-space laser communications. This system will be used by NASA’s Mars Laser Communications Demonstration project on the Mars Telecommunication Orbiter, the first use of high-speed laser communication from deep space. The error-correction code design has been shown to perform within 0.9 d...

We demonstrated a method to trim the beat frequency of dual-polarization fiber grating lasers by side-exposing the laser cavity to UV beam. The UV-side-illumination induces an additional birefringence of the cavity fiber and therefore permanently changes the beat frequency of the laser. The beat frequency can be trimmed up or trimmed down, depending on the UV incident direction relative to the ...

We have developed a laser photodiode array based detection system that can nonintrusively detect delineations of vehicles on the highway. The U.S. Patent Office has recently approved a patent for this detection system. The system is built with low-cost off-the-shelf opto-mechanical components. The error sources from a system design point of view will be analyzed in this paper. Our study indicat...

We report the generation of dual-wavelength picosecond pulses by use of a commercial laser-diode array. The laser cavity incorporated a folded dispersive delay line with a V-shaped double-stripe mirror. The spectral separation of the laser output at the two wavelengths can be tuned from 2 to 11 nm. The actively mode-locked pulse widths at the two wavelengths were both 29 ps. Cross-correlation a...

We propose a design for programmed molecular interactions that continuously change molecular arrangements in a predesigned manner. We introduce a model where environmental control through laser illumination allows platform attachment/detachment oscillations between two floating molecular species. The platform is a two-dimensional DNA origami array of tiles decorated with strands that provide bo...

Ultrafast electron pulses can be produced from sharp metallic tips illuminated by femtosecond near infrared laser pulses. Use of an array of metallic nanotips for high charge bunch generation and accelerator applications is also feasible but the small fraction of the emitter tip area limits the quantum efficiency. We therefore propose a submicron-pitch, high-density nanotip array device with a ...

The optical characteristics of phase-locked semiconductor laser arrays are formulated in terms of the array supermodes, which are the eigenmodes of the composite-array waveguide, by using coupled-mode theory. These supermodes are employed to calculate the near fields, the far fields, and the difference in the longitudinal-mode oscillation wavelengths of the array. It is shown that the broadenin...

We report the use of a 50-mW peak power 4.3-THz quantum cascade laser (QCL) as an illumination source for realtime imaging with a 320 240 element room-temperature microbolometer focal-plane array detector. The QCL is modulated synchronously with the focal-plane array for differential imaging. Signal-to-noise ratios of 340 are achieved at a 20-frame/s acquisition rate, and the optical noise equi...

We have designed and fabricated a compact array-based optical engine for transmitting data at 10 Gb/s. The device consists of a 4-channel ASIC driving a VCSEL (Vertical Cavity Surface Emitting Laser) array in an optical package. The ASIC is designed using only core transistors in a 65 nm CMOS process to enhance the radiation-hardness. The ASIC contains an 8-bit DAC to control the bias and modul...

n la década de los ochenta se introdujo en el mercado una nueva tecnología para la implantación de sistemas digitales: los arreglos de compuertas programables en campo (FPGA, "Field Programmable Gate Array"). Estos dispositivos ofrecen varias ventajas con respecto a los componentes discretos de mediana y alta escala de integración (MSI/LSI) y de aplicación específica. Los FPGA son capaces de op...