Diode Laser Sensor Research Articles

Carbon monoxide over the Amazon Basin during the 1985 dry season

During the Amazon Boundary Layer Experiment (ABLE 2A), approximately 100 hours of in situ, carbon monoxide (CO) measurements were obtained using a tunable diode laser sensor that provided continuous, fast‐response (≈1 s) measurements. This extensive data set, taken on board the NASA Electra between July 12 and August 12, 1985, characterizes the temporal and spatial changes in the CO distribution over the Amazon basin as meteorological conditions progressed from the early to middle phases of the 1985 day season. Early dry‐season CO values of 75–95 parts per billion by volume (ppbv) were generally observed in the planetary boundary layer (PBL). As the dry season became well established, biomass burning and a persistent capping inversion at ≈3 km profoundly altered the CO distribution, with PBL values typically reaching 150–275 ppbv. Concentrations as high as 800 ppbv were measured within identifiable haze layers. An analysis of satellite imagery shows that biomass burning was occurring along the Amazon River system and in savannah areas located more than 1000 km south of the region sampled.

Optical Fiber Sensor Technology

The current state of the art of optical fiber sensors is reviewed. The principles of operation are detailed and the various types of fiber sensors are outlined. Achievable performance and limitations are discussed and a description of technology used to fabricate the sensor is presented. The characteristics of acoustic, magnetic, gyro, laser diode, and other sensors are described. Trends in the development of this sensor technology and expected application areas are briefly outlined.

Optical fiber sensor technology

The current state of the art of optical fiber sensors is reviewed. The principles of operation are detailed and the various types of fiber sensors are outlined. Achievable performance and limitations are discussed and a description of technology used to fabricate the sensor is presented. The characteristics of acoustic, magnetic, gyro, laser diode, and other sensors are described. Trends in the development of this sensor technology and expected application areas are briefly outlined.

Phase sensitivity and linewidth narrowing in a Fox–Smith configured semiconductor laser

The behavior and spectral characteristics of a constricted double heterojunction injection laser in a regime in which the lasing characteristics are dominated by a cavity comprised of two external mirrors is reported. The Fox–Smith configuration is shown to limit the laser’s emission (previously multimode) to a single longitudinal mode with a linewidth of less than 200 kHz. It is also shown that this laser interferometer configuration is effective as an extended, external cavity laser diode sensor.