Abstract: In accordance with the invention, a high-resolution variable optical delay line comprises an optical switch, such as an optical micromechanical mirror switch, and an array of delay fiber paths. Each delay fiber path in the array comprises a region where the fiber is curved differently from the other fibers in the region and a reflector. Each fiber path advantageously comprises other regions where the fiber is essentially parallel to the other fibers in the region. Each fiber is curved differently from the others in order that the fiber paths each provide a different delay.

Abstract: In accordance with the invention, the optical power level in an optical waveguide is monitored by enclosing a length of the waveguide within an insulated cavity of comparable length and cross section, measuring a first temperature T1 within the cavity, measuring a second temperature T2 outside the cavity and deriving from the difference, T1−T2, a measure of the optical power level. Exemplary apparatus for monitoring the optical power level in an optical waveguide comprises a substrate with an insulated groove for receiving an optical fiber, an insulated lid for sealing the fiber within the groove, and internal and external temperature sensors.

Abstract: In accordance with the invention, the optical power level in an optical waveguide is monitored by enclosing a length of the waveguide within an insulated cavity of comparable length and cross section, measuring a first temperature T1 within the cavity, measuring a second temperature T2 outside the cavity and deriving from the difference, T1−T2, a measure of the optical power level. Exemplary apparatus for monitoring the optical power level in an optical waveguide comprises a substrate with an insulated groove for receiving an optical fiber, an insulated lid for sealing the fiber within the groove, and internal and external temperature sensors.

Abstract: In accordance with the invention, a high-resolution variable optical delay line comprises an optical switch, such as an optical micromechanical mirror switch, and an array of delay fiber paths. Each delay fiber path in the array comprises a region where the fiber is curved differently from the other fibers in the region and a reflector. Each fiber path advantageously comprises other regions where the fiber is essentially parallel to the other fibers in the region. Each fiber is curved differently from the others in order that the fiber paths each provide a different delay.