Douglas Warren Hall

Nonlinear optical susceptibilities of high‐index glasses

We report results of degenerate four‐wave mixing measurements of nonresonant nonlinearities in a variety of high‐index lead and bismuth containing oxide glasses and the chalcogenide As2S3. The third‐order nonlinear susceptibilities of the oxide glasses are found to scale with the heavy metal content. A lead‐bismuth‐gallate glass was identified with a nonresonant χ3 equal to 42±7×10−14 esu, which is approximately three times larger than that of any glass previously reported.

Absorption saturation in commercial and quantum-confine CdSexS 1− x-doped glasses

The optical nonlinearity of commercial and experimental CdSexS1−x glasses has been studied using a single-beam absorption saturation technique employing 1−5-psec pulses. Glasses showing strong three-dimensional quantum-confinement effects were found to be more difficult to saturate than glasses with larger crystallites that exhibit bulk crystallike optical properties. The effect of anion stoichiometry on the nonlinearity was also studied in non-quantum-confined glasses. Within the range 0.48 < x ≤ 1.0, little difference in nonlinearity was observed.

Enhanced-nonlinearity single-mode lead silicate optical fiber.

A single-mode lead silicate optical fiber has been fabricated to permit lower-power all-optical switching. The core glass has a nonlinear index of refraction eight times that of silica. The loss of the fiber is less than 2 dB/m. Over 177pi of phase shift was obtained, as measured by self-phase modulation, in a 29-cm length of fiber. At the 1-kW peak power level required to produce this large phase shift, two-photon absorption and stimulated Raman scattering did not significantly degrade the desired nonlinear behavior.

Comparison of Nd3+-doped glasses for amplification in the 1300-nm region

Excited-state-absorption and stimulated-emission cross-section spectra have been measured in the 1300-nm region for a wide variety of Nd3+-doped glass compositions. The results indicate that fluoroberyllates are the best choice for fiber amplifiers in the 1300-nm optical communications window. Model calculations predict a gain spectrum peaked at 1314 nm with useful gain extending from 1304 to 1370 nm when amplified spontaneous emission is neglected.

EFFECTS OF PACKAGING ATMOSPHERE AND ORGANIC CONTAMINATION ON 980 nm LASER DIODE RELIABILITY

Diode lasers at 980 nm are a favored power source for Er-doped fiber amplifiers. Conditions of amplifier deployment require that the laser pumps be hermetically sealed and reliable for >105 hr. Many amplifier systems currently under design or test require >70 mW of fiber coupled power (Po), which corresponds to very high facet power densities in excess of five megawatts/cm2.