Showing papers by "Yoshiyasu Ueno published in 1997"

Semiconductor laser device operable with low noise even in high ambient temperature

Abstract: In a semiconductor laser device comprising a plurality of semiconductor layers laminated in a vertical direction on a substrate to form a laser resonator, the laser resonator comprises a saturable absorbing region. A spot size of a light waveguide profile in the vertical direction is greater than 0.4 μm. The laser resonator further comprises first and second reflecting films to provide a reflectivity greater than 50(%).

Large Phase Shifts due to the $\mbi \chi ^{\bf (2)}$ Cascading Nonlinearity in Large Walk-off and Loss Regimes in Semiconductors and Other Dispersive Materials

Abstract: The nonlinear phase shift associated with χ(2) cascading was studied for ultrashort pulses in regimes with large temporal walk-offs between the fundamental and the χ(2)-generated second-harmonic (SH) pulses, a situation typical of semiconductors. Despite the small overlap between the fundamental and SH pulses after they walk-off each other, a nonlinear phase shift was numerically observed to occur at a rate comparable to that before they walk-off. A π/2 phase shift was demonstrated even in a waveguide 15 times longer than the walk-off length.

Semiconductor laser used in optical communication system

Abstract: The semiconductor laser has some laminated semiconductor layers. A saturable absorber is formed inside the laser resonator. The spot size of the optical waveguide style in the laminated layer exceeds 0.4microns. The reflecting rate of the optical radiation front end surface (31) and rear end surface (32) exceeds 50%.