摘要:

Ultrafast gain dynamics in GaAlAs diode amplifiers have been studied using 100 fs optical pulses. Pulse propagation through the amplifier resulted in temporal broadening and pulse shaping due to both gain saturation and material dispersion. Pump‐probe experiments indicate the presence of two processes contributing to the gain dynamics but give no evidence of spectral hole burning. A dynamic carrier heating model is presented to explain all of the observed gain nonlinearities, and the implications of our results on the dynamic response of laser diodes are discussed.

ISSN:0003-6951    

DOI:10.1063/1.98515

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Multiple wavelength oscillation at 0.91, 1.08, 1.53, and 1.55 &mgr;m has been simultaneously obtained in a fusion‐spliced silica‐based fiber laser consisting of Er3+‐doped and Nd3+‐doped fibers. The laser mirrors, which are butted against the cleaved fiber ends, have high reflectivities at these wavelengths with a high transmission at a pumping wavelength of 514 nm. The output powers at 0.91, 1.08, and 1.53 &mgr;m are 2.0, 1.7, and 0.42 mW, respectively, for absorbed powers of 115 mW in a Nd3+‐doped fiber and 185 mW in an Er3+‐doped fiber.

ISSN:0003-6951    

DOI:10.1063/1.98516

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A scheme for phase‐locked laser arrays in both one‐ and two‐dimensional configurations is discussed. The scheme can be applied to any laser and its validity has been proved for the case of a pulsed neodimium laser.

ISSN:0003-6951    

DOI:10.1063/1.98517

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A 1.3‐&mgr;m GaInAsP/InP buried crescent laser on ap‐type InP substrate was demonstrated. An active region width narrower than 1.5 &mgr;m was achieved with good controllability and reproducibility using the newly introduced reactive ion beam etching technique for the etching process. Stable fundamental transverse mode operation with low threshold currents of 15–25 mA was obtained. Less than 5% degradation in threshold current at 50 °C was achieved with a constant driving current of 150 mA at 70 °C for 100 h.

ISSN:0003-6951    

DOI:10.1063/1.98518

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A complete set ofand,or,nand,nor, andinvertlogic gates is demonstrated using a distributed feedback (DFB) injection laser with two‐electrode current control. The logic operation is based on the high‐speed two‐wavelength switching using the two‐mode degeneracy property of DFB lasers that we have demonstrated recently. A 400‐ps switching time, limited by the speed of the electrical signal, was observed. The device is compatible with future photonic integrated circuit and wide‐band optical fiber transmission technologies.

ISSN:0003-6951    

DOI:10.1063/1.98519

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A new semiconductor laser optical logic gate based on quenching and capable of performing thenot,nor, andnandfunctions is described. The device can be operated both pulsed and cw at room temperature. In addition, the new logic gate can be monolithically integrated.

ISSN:0003-6951    

DOI:10.1063/1.98520

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The fabrication and performance of high‐speed and high‐power 1.3‐&mgr;m InGaAsP buried crescent lasers with semi‐insulating current blocking layers are reported. A modulation bandwidth of 11 GHz and acw output power of 42 mW/facet have been achieved. An approximate circuit model of the semi‐insulating buried crescent laser, which describes the effect of dc bias on parasitic capacitance at high‐speed operation, is also presented.

ISSN:0003-6951    

DOI:10.1063/1.98521

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We have observed an intensity‐dependent shift in the exciton absorption features for a system of coupled quantum wells in which a thin barrier separates two wells of unequal widths. We found that for a fixed external bias on the sample, the normal quantum Stark shift of the excitons in the wells was suppressed when light of 1 &mgr;W/cm2intensity was used to measure the absorption. The shift became systematically larger as the light intensity was decreased to as low as 100 pW/cm2. This extremely low‐level nonlinearity may be due to internal fields that arise when free electrons and holes are separated within the coupled‐well system.

ISSN:0003-6951    

DOI:10.1063/1.98522

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Significant spectral broadening of the photoluminescence in GaSe under the picosecond‐laser‐driven shock pressure has been observed for the first time. The broadening of the spontaneous emission was found to be proportional to the shock pressure and attributed to a shock‐wave‐induced exciton collision mechanism due to the directional motion of particles in the shocked region.

ISSN:0003-6951    

DOI:10.1063/1.98523

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A self‐consistent model for semiconductor lasers [using the channeled‐substrate‐planar (CSP) double‐heterojunction (DH) laser as an example] which does not assume constant optical power along the laser axis is developed. This approach allows for the analysis of high‐power lasers with low facet reflectivities which produce nonuniform photon densities along the propagation direction. Analytical equations for the modal gain coefficient, the threshold current density, and the radiated power for a specific CSP laser structure are obtained.

ISSN:0003-6951    

DOI:10.1063/1.98524

出版商:AIP    

年代:1987

数据来源: AIP