Ramon P. DePaula

Strategies for telecommunications and navigation in support of Mars exploration

Abstract The planned exploration of Mars will pose new and unique telecommunications and navigation challenges. The full range of orbital, atmospheric, and surface exploration will drive requirements on data return, energy-efficient communications, connectivity, and positioning. In this paper we will summarize the needs of the currently planned Mars exploration mission set, outline design trades and options for meeting these needs, and quantify the specific telecommunications and navigation capabilities of an evolving infrastructure.

Interferometric Fiber Optic Gyroscope Using a Novel 3x3 Integrated Optic Polarizer/Splitter

A Ti:LiNbO3 3x3 directional coupler, acting as both polarizer and 3db splitter, with a phase modulator has been incorporated in an interferometric fiber optic gyroscope. A random walk performance of 1x10^-20h has been demonstrated.

Overview of NASA R+D in Optical Communications

We review the current applications base for the use of free-space optical communications technology. We then describe the NASA programs in the optical communications area addressing those applications areas. In particular, we describe the Laser Communications Demonstration System, an industry-driven program for the space-demonstration of this technology at data rates of at least 750 Mbps. We then describe NASA technology development and study activities in support of these applications. Activities described include the Optical Communications Demonstrator, a study of an air-to-ground system demonstration, a mission application study for the TOPSAT radar mapping mission, and a program to acquire detailed statistics on atmospheric transmission for space-to-ground links.

Current trends in fiber optic sensor technology

Current trends of fiber optic sensor technology are in a direction of a broadening scope of sensor innovation based on a few basic concepts. Both single-mode and multimode fibers have their proponents: single mode for primarily interferometric sensors and multimode for primarily amplitude-modulated sensors. This paper illustrates four unique and innovative multimode sensor designs and also discusses the basic inhibition to more rapid utilization of optical fiber sensors. A case is made for more effort in standardization of optical fiber sensor interface design and integration requirements. To benefit the optical fiber sensor R & D and small business community, attention to system level requirements is necessary to encourage greater utilization and achieve greater exploitation of the benefits offered by optical fiber sensors.

Photonics Technology for Space Communications Applications

Photonics technology offers a multitude of applications and major benefits in the development of future spaceborne communications systems with high performance and low mass/size requirements. These applications include not only signal distribution/control functions, but also optical signal processing, phased array antennas, sensors, instruments, and gyros.

Integrated optics for fiber optic sensors

Recent progress achieved in the field of fiber-optic sensor applications is discussed with emphasis placed on LiNbO3-based integrated optics (IO). Particular consideration is given to advanced electromagnetic-field sensors, an integrated laser vibrometer system, and a fiber-optic gyroscope system. It is shown that the multifunction IO chips have enabled high perforamance fiber-optic sensors (e.g., fiber-optic gyros), provided advanced and unique signal processing capabilities and advanced architectures, and have a potential of making fiber-optic sensors at low cost.