Optical coherence tomography using a frequency-tunable optical source.

We have developed a simple, wide-optical-bandwidth, high-resolution system for performing rapid optical frequency domain reflectometry measurements and applied it to multidimensional tomographic imaging. The source is a grating-tuned external cavity semiconductor laser with a tuning capability of 25 nm in 100 ms. We discuss system performance and show a two-dimensional optical coherence tomography image of a thin glass sandwich structure as a preliminary demonstration of the systems depth and resolution capabilities.

Multilayer optical storage by low-coherence reflectometry.

We propose and analyze the use of optical coherence domain ref lectometry (OCDR) in multilayer optical storage, permitting higher data density and detection sensitivity with lower interlayer cross talk and scattering. An experimental OCDR image of data on a CD-ROM is compared with an image obtained with direct detection.

Differential coupled mode analysis and the Poincare sphere.

The use of Poincare sphere visualization of two-coupled-mode problems is reviewed, and a new vector form of the usual integrated optics differential equations is presented. Unlike previous similar treatments involving propagation over discrete uniform intervals, we show the relationship of the differential form of the coupled mode equations to the Stokes-Mueller formalism, using the Feynman-Vernon-Hellwarth method for the twolevel Schrodinger equation. A specific example is given for the tuned fiber coil optical isolator, for which the present method allows a solution by inspection.

Differential coupled mode analysis and the Poincare sphere: erratum.

This erratum Letter notes a previous derivation of the differential coupled mode analysis.

Dynamically stable 0 degrees phase mode operation of a grating-surface-emitting diode-laser array.

A coherent grating-surface-emitting diode-laser array has demonstrated dynamically stable operation in the 0 degrees phase mode. The array was operated under pulsed conditions, had a peak power output of 44 mW and a large central lobe on axis in the far field, and exhibited single-mode spectral output with better than 18-dB side-mode rejection.

Low-threshold transversely excited NdP(5)O(14) laser.

The threshold and efficiency of a transversely excited, cw NdP(5)O(14) laser have been measured with 0.58-microm excitation from a dye laser and 0.8-microm excitation from a semiconductor laser. After fitting our data for the threshold as a function of wavelength near 0.58 microm, we have applied the calculations to the 0.80-microM Nd(3+) absorption band. With transverse excitation from high-radiance LED's or laser diodes, thresholds are calculated to be 4-8.5 mW at 0.80 microm, depending on pump bandwidth. Using an A1(x)Ga(1-x)As double-hetero-structure laser diode pump, we have obtained quasi-cw lasing in NdP(5)O(14), with thresholds ~7 mW and optical power conversion efficiency ~7%.