Diode laser transmitter for water vapor DIAL measurements

The design and performance of two diode laser based transmitters for differential absorption LIDAR (DIAL) are presented. The first laser transmitter uses a tunable external cavity diode laser (ECDL) in the Littman-Metcalf cavity configuration to injection seed a flared amplifier. Water vapor absorption measurements are demonstrated with this laser transmitter operating in a continuous wave mode. The second diode based laser transmitter uses an ECDL in the Littrow cavity configuration and angle-angle semiconductor optical amplifiers to produce amplified laser pulses. Both designs are easily adaptable to wavelengths in the visible to the near infrared spectral region.