HIGH-POWER SEMICONDUCTOR EDGE-EMITTING LIGHT-EMITTING-DIODES FOR OPTICAL LOW-COHERENCE REFLECTOMETRY

A new semiconductor source was designed for optical low coherence refl ectometry, increasing the sidelobe-free dynamic range by three to five orders of magnitude compared to conventional EELED's. Reflectivities internal to an optical fiber circuit separated by as much as eight ord ers of magnitude can now be detected at wavelengths of 1.3 and 1.55 mu m, using compact semiconductor sources, For applications not requirin g sidelobe- free operation, the same devices can be operated at high c urrent (200 mA) and low temperatures (near 0 degrees C) to produce nea rly 1 mW of 1.5 mu m emission coupled into single-mode fiber, The resu lting wavelength spectrum is smooth, enabling fiber-based absorption, spectral measurements.