Abstract: A laser Doppler velocimeter is formed using erbium-doped fiber as the lasing medium. The fiber is diode-pumped. By properly modulating the lasing in the fiber, pulses of radiation may be generated. A telescope acts as the transmission device to focus the radiation at a specified point, and may also act as the receiving system for reflected radiation. The portion of the reflected radiation collected by the receiving system is analyzed to determine the Doppler shift caused by aerosols or objects at the focal point of the telescope.

Abstract: An optical fiber has a small diameter core for transmitting one or more wavelength multiplexed first light signals in a first direction, and an inner cladding for transmitting a second light signal in the opposite direction. A lower-index outer cladding or buffer is used to confine the second signal in the first cladding. The diameter of the core may be less than about ten microns. A notch, prism or other suitable device extends into the first cladding and is used to reflect the second signal into an input/output fiber. The reflective device may also be used to input additional light energy into the first optical fiber, to thereby augment an outgoing beam. The optical fiber system may be used in combination with a multi-function signal generating system mounted on an aimable device. A lens device may be used to collimate the outgoing beam and to converge a reflected return beam onto the end of the first fiber.