Optical Trap Detector for Calibration of Optical Fiber Powermeters: Coupling Efficiency

Published

November 1, 2002

Author(s)

John H. Lehman, Christopher L. Cromer

Abstract

The optical trap detector is based on two 1 cm x 1 cm silicon photodiodes and a spherical mirror contained in a package that is highly efficient for measuring light diverging from the end of an optical fiber. The mathematical derivation of the coupling efficiency relies on the integral directional response weighted by the angular intensity distribution of an idealized parabolic optical beam. Results of directional-uniformity measurements, acquired with the aid of a 6-axis industrial robotic arm, indicate that the trap has a collection efficiency greater than 99.9% for a fiber numerical aperture of 0.24. Spatial uniformity measurements indicate that the variation of detector response as a function of position is less than 0.1%. The detector's absolute responsivity at 672.3, 851.7, and 986.1 nm is also documented by comparison with other optical detectors and various input conditions and indicates that the design is well suited for laser and optical fiber power measurements.

Citation

Optics Letters

Volume

41

Issue

31

Pub Type

Journals

Keywords

coupling effiency, optical detector, optical fiber power measurement, uncertainty

Citation

Lehman, J. and Cromer, C. (2002), Optical Trap Detector for Calibration of Optical Fiber Powermeters: Coupling Efficiency, Optics Letters (Accessed July 26, 2024)