摘要:

Gain characteristics of Er3+‐doped fibers for different pump wavelengths between 1.455 and 1.510 &mgr;m are investigated to obtain the optimum pump wavelength. It is found that the efficient pump wavelengths are located in the 1.460–1.475 &mgr;m range for Er3+‐doped Al2O3‐GeO2‐SiO2and Er3+‐doped GeO2‐SiO2fibers, where a maximum gain of about 27 dB was obtained with an absorbed pump power of 31 mW.

ISSN:0003-6951    

DOI:10.1063/1.103141

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We report on the synchronous pumping of an optical parametric oscillator (OPO) using a frequency‐doubled, mode‐locked, andQ‐switched diode laser pumped yttrium lithium fluoride laser. Using a 1 W pump diode, frequency modulation mode locking, and acousto‐opticQswitching, a pulse envelope of 75 ns duration and 45 &mgr;J of energy in 21 ps pulses at 360 MHz repetition rate was obtained. This was frequency doubled in 90° phase‐matched MgO:LiNbO3with 47% energy conversion efficiency. The doubly resonant OPO based upon temperature‐tuned MgO:LiNbO3had an energy conversion efficiency of 20% at degeneracy. The tuning range of 983–1119 nm was limited by the mirror reflectivities.

ISSN:0003-6951    

DOI:10.1063/1.103142

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A U‐shaped GaAs/AlGaAs laser diode (LD) with totally reflecting mirrors is fabricated. Reactive fast atom beam etching technique with Cl2gas is applied to fabricate the totally reflecting mirrors. Continuous‐wave operation of the U‐shaped LD with two totally reflecting mirrors is achieved using a graded‐index separate‐confinement‐heterostructure single quantum well laser wafer. A threshold current of 75 mA and a light output power of over 5 mW are obtained with a 40‐&mgr;m‐wide and 300‐&mgr;m‐long mesa stripe structure. Totally reflecting mirror loss is estimated from measurements of the threshold current density for different cavity lengths. The loss of the totally reflecting mirror is about 0.95 dB per reflection.

ISSN:0003-6951    

DOI:10.1063/1.103143

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We propose a new distributed feedback (DFB) laser structure in which almost pure gain coupling can be embodied in principle, without sacrificing low threshold operation. An analysis of coupling coefficients has revealed the condition for canceling index‐coupling component. Utilizing organometallic vapor phase epitaxy, we have fabricated GaAlAs/GaAs ridge waveguide distributed feedback lasers having this structure. Excellent single longitudinal mode oscillation independent of facet reflection has been obtained along with low threshold current. The single‐mode spectrum has exhibited distinctive characters of purely gain‐coupled DFB lasers.

ISSN:0003-6951    

DOI:10.1063/1.103144

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We describe the fabrication and characteristics of closely spaced (10 &mgr;m) dual‐beam laser sources by the process of impurity‐induced disordering. We present data demonstrating that these devices are capable of high efficiency and reliable operation when operated in ap‐side up configuration. We also show that these devices can be placed in close proximity with a minimal amount of thermal and electrical interaction between devices. These features have significant implications for the realization of high‐density arrays of independently addressable lasers for optical interconnection of integrated circuits and optical imaging systems.

ISSN:0003-6951    

DOI:10.1063/1.103145

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

An asymmetric Fabry–Perot structure with a multiple quantum well active region is demonstrated to provide a reflection change of >45% for an operating voltage swing of only ∼2 V, with a contrast ratio of more than 15. Photocurrent measurements show that the same devices also work as voltage‐tunable detectors. Such devices compete effectively with low‐voltage waveguide modulators, with further advantages of easy coupling and compact sizes, i.e., small capacitances.

ISSN:0003-6951    

DOI:10.1063/1.103146

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Single and multiple quantum well laser diodes operating at 1.5 &mgr;m are fabricated incorporating an intracavity electroabsorptive loss modulator. Absorption in the diode laser cavity is modulated by a femtosecond dye laser used to generate picosecond electrical transients. Two types of electrical excitation are provided to the modulator: a pulse, using an integrated PIN photodiode and a step, using an integrated photoconductive switch. The full width at half maximum (FWHM) for 100% laser modulation is 53 ps. Direct excitation of the loss segment resulted in pulse widths of 38 ps FWHM and 100% modulation.

ISSN:0003-6951    

DOI:10.1063/1.103147

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

It is shown that cadmium telluride exhibits second‐harmonic generation under 1064 nm ps pulse excitation despite strong absorption of the green light which is generated. The process of second‐harmonic generation contributes to the creation of an electron‐hole plasma in CdTe which affects the measured value of the two‐photon absorption coefficient and other nonlinear properties of the material.

ISSN:0003-6951    

DOI:10.1063/1.103148

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Diode‐pumped cw lasing at 2.71, 2.75, and 2.78 &mgr;m from an erbium‐doped ZBLAN single‐mode fiber is reported for the first time. A threshold of 4 mW absorbed power at 792 nm was obtained for the 2.71 &mgr;m transition. 3% slope efficiency was obtained with an 80% reflecting output mirror. cw lasing was also observed from the fiber when a tunable pump was scanned across most of the4I15/2→4I9/2absorption band. cw lasing observed when pumping around 820 nm indicates that excited‐state absorption of the pump from the4I13/2may not be necessary for cw operation. However, excited‐state absorption of the pump around 810 nm from the4I11/2may limit performance.

ISSN:0003-6951    

DOI:10.1063/1.103149

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Surface interference, nonlinearly saturated instability of laser‐induced thermodestruction, and subsequent oscillation of absorption mode permit the description of analytical ablation thresholds and depths per pulse of polymers having high absorption at laser wavelengths, e.g., polyimide and poly(ethylene terephtalate). Inverse problem solution for polycarbonate and ablation invariant designing are also realized.

ISSN:0003-6951    

DOI:10.1063/1.103150

出版商:AIP    

年代:1990

数据来源: AIP