摘要:

The phase‐locking characteristics of two coupled, ridge waveguide InP/InGaAsP diode lasers emitting at 1.2 &mgr;m were investigated experimentally. The phase locking of the lasers was verified by the observation of phase‐locked modes (supermodes) in the spectrally resolved near fields and distinct diffraction patterns in the far field. By independent control of the laser currents it was possible to vary continuously the mutual phase shift between the two phase‐locked lasers and thus steer the far‐field diffraction lobes. In addition, the separate current control could be utilized to obtain single longitudinal mode oscillation of the phase‐locked lasers. Variation in one of the laser currents resulted then in tuning of the wavelength of this single mode over a range of 90 A˚.

ISSN:0003-6951    

DOI:10.1063/1.95087

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We show that mode cutoff can occur at finite powers for waves guided by a thin‐film waveguide bounded by one or two media characterized by a defocusing nonlinearity. This phenomenon produced optical limiting action.

ISSN:0003-6951    

DOI:10.1063/1.95088

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A device to measure water particle velocity in two directions under a breaking water wave was developed using single‐mode, polarization‐preserving fibers in conjunction with a two‐color, three‐beam laser‐Doppler anemometer. The sensor uses backscatter method with two beams frequency shifted to measure velocity reversal in both directions.

ISSN:0003-6951    

DOI:10.1063/1.95089

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Atmospheric pressure operation of a KrF laser pumped by 50‐ns electron beams was experimentally investigated. For a 1‐atm mixture of Kr and F2without diluent, a specific output energy of 4.2 J/1 was obtained at 1.7‐MW/cm3excitation rate. Under this condition the intrinsic efficiency was about 5% (6% was maximum at 20% Kr in argon diluent) which was comparable to that from 1‐atm normal (10% Kr) mixtures.

ISSN:0003-6951    

DOI:10.1063/1.95090

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A traveling‐wave Ti‐indiffused LiNbO3guided‐wave Mach–Zehnder interferometric modulator has been fabricated and characterized at &lgr;=0.85 &mgr;m. The modulator achieves the theoretical 3‐dB linear small‐signal bandwidth limit of 16 GHz for a 4‐mm‐long interaction length. With a ±2.25‐V drive signal, an extinction ratio of 22 dB is achieved. Linear small‐signal measurements made with a swept‐frequency technique are compared to previously reported measurements.

ISSN:0003-6951    

DOI:10.1063/1.95091

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report the first successful mode locking of a cw neodymium phosphate glass laser. Transform‐limited, 80‐ps pulses were generated at 1.054 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.95092

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report an analysis of the phenomenon of TE to TM mode conversion in LiNbO3waveguides. The process is a consequence of the photorefractivity associated with the tensor character of the photovoltaic effect. We predict the existence of a nonlinear phase shift during the energy transfer process as well as a threshold behavior in the dynamics of energy exchange.

ISSN:0003-6951    

DOI:10.1063/1.95081

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Fast, sensitive, and selective fingerprint detection of organometallics, with emphasis on dimethyltelluride CH3TeCH3, is described, using short and ultrashort pulse tunable dye laser controlled time‐of‐flight mass spectroscopy. Excellent spatial (∼10 &mgr;m) and time (≪1 ns) resolutions combined with highsingleshotselectivity and sensitivity down to 10−7Torr and below (corresponding to 3×109cm−3or about 3000 molecules in the observation region)plusmass identification are obtained.

ISSN:0003-6951    

DOI:10.1063/1.95082

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Optical and modulation properties of ridge waveguide distributed feedback lasers grown by liquid phase epitaxy and operating in the spectral region of 1.51–1.58 &mgr;m have been investigated. These lasers were characterized by room temperature cw threshold currents as low as 40 mA, external quantum efficiency of up to 40%, and lowest order transverse mode operation up to 10 mW. Stable, single longitudinal mode operation under direct modulation of up to 4 GHz was obtained using second order gratings fabricated by electron beam writing as well as optical holography. The absence of partition mode events has allowed routine error free transmission over 60 km of single mode fiber at data rates of 2 Gb/s. The relationship between grating parameters and the Bragg length has been studied experimentally and compared with the theoretical results.

ISSN:0003-6951    

DOI:10.1063/1.95083

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A new technique is described to measure temporal periodic fluctuations in the free‐carrier density of silicon. It is based on the electronic dependence of the elastic constants, and involves the measurement of the perturbation in phase of an acoustic wave propagating through a region of modulated carrier density. An experiment is described in which the bulk lifetime of photogenerated carriers is determined using this technique. A theory is developed to predict the acoustic phase perturbation, and is found to agree well with experiment.

ISSN:0003-6951    

DOI:10.1063/1.95084

出版商:AIP    

年代:1984

数据来源: AIP