摘要:

Recently, the mechanisms leading to the resonant Kerr nonlinearity of Cd(S,Se)‐doped glasses could clearly be assessed. On this basis, we reconsider experimentally the size dependence of the fast component of this nonlinearity. We observe that the figure of merit corresponding to this fast component decreases when the particle size decreases. The various results that had been previously reported are discussed in light of this work. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115394

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

In this paper we will explain the preparation of an epitaxially grown ytterbium‐ and neodymium‐co‐doped yttrium aluminum garnet [(Yb,Nd):YAG]–buried channel waveguide laser on a YAG substrate. Waveguides, whose cores are formed with Ar ion beam etching, demonstrate single‐mode operation. The (Yb,Nd):YAG waveguide laser operates at 1.03 &mgr;m when pumped at 0.81 &mgr;m, as a result of a nonradiative energy transfer from Nd3+ions to Yb3+ions. The incident threshold and slope efficiency of the 5 mm long waveguide laser are 235 mW and 13%, respectively. Output power of 50 mW is obtained for an incident power of 620 mW at room temperature. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115395

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We report the experimental observation of butterfly bistability in an InGaAs/InP multiple‐quantum well waveguide with a distributed feedback grating, under cw operation and at sub‐milliwatt input power. Plasma effects on the excitonic optical properties in multiple‐quantum well structures are the basis of the observed bistability. Insight provided by a simple coupled‐mode description of the device and by many‐body theory of the field‐matter interaction is used both for device design and for interpretation of the results. In particular, the unconventional shape of the hysteresis is due to increased optical absorption at high injected optical power. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115396

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Transmission system experiments using surface emitting lasers (SEL) and integrated photoreceivers have been carried out. The surface emitting laser utilizes proton implantation for current confinement and has a small signal bandwidth of 10 GHz. Thep‐i‐n/modulation doped field effect transistor photoreceiver has a bandwidth of 11 GHz. Bit error rates of less than 10−9were demonstrated using the SEL source and the photoreceiver. The receiver sensitivity is −16.5 dBm at 10 Gb/s. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115397

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Wavelength‐tunable light emission is demonstrated from a planar microcavity employing a deformable‐membrane top mirror. A gold/silicon nitride membrane is suspended by an air gap above a GaAs cavity, containing In0.2Ga0.8As multiple quantum wells, and a GaAs/AlAs distributed Bragg reflector. Micromechanical displacement of the membrane allows for broad and continuous wavelength tuning of the cavity resonance formed by the combination of the semiconductor cavity and the air gap. Optically excited luminescence from the quantum wells is restricted to the resonant cavity modes and exhibits a 31 nm (42 meV) tuning range and 2.2 nm (3 meV) linewidth near 960 nm for 0–15 V applied bias. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115398

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We have demonstrated a thermally compensated KTiOPO4(KTP)Q‐switch with a 10 mm × 6 mm clear aperture and high contrast ratio. This device showed excellent resistance to thermal depolarization at average power densities as high as 1 kW/cm2. Capacitive coupling allowed us to operate theQ‐switch for greater than 109shots with no sign of electrochromic damage. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115399

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We demonstrate a new approach to determine the dielectric tensor of anisotropic materials using a rotating polarizer (or analyzer) ellipsometer. The dependence of the ellipsometric parameters as a function of azimuthal angle shows characteristic patterns very sensitive to the magnitude of the dielectric tensor and its orientation with respect to the sample surface. These patterns are in general nonsinusoidal and depend strongly on the angle setting of the fixed analyzer (or polarizer). We illustrate the method with results obtained on a generic crystallographic face of a uniaxial material, namely, a single crystal of the electron‐doped high‐temperature superconductor Nd1.85Ce0.15CuO4−&dgr; . ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115400

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We report a convenient method to obtain all‐optical light modulation in bacteriorhodopsin films using a degenerate four‐wave mixing geometry. Chemically stabilized films of bacteriorhodopsin in a polymer matrix for which the lifetime of the excitedMstate is tens of seconds were used to demonstrate all‐optical light intensity modulation. The films are observed to be stable over a period of 4 years. Due to the sensitivity of the films, small intensities of order microwatt/ cm2are required in the modulation experiments. Furthermore the fast photochemical transition fromMtoBpermit reasonably fast modulation speeds independent of the slow thermalMandBrelaxation time. The experimental system also acts as an all‐optical switch where a low power blue pulse turns on a signal red beam. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115401

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We have directly and passively generated a 290‐nm, 600‐ps pulse train from a Ce:LiCAF laser pumped by the fourth harmonic of a conventional 10‐nsQ‐switched Nd:YAG laser. This simple, all‐solid‐state, short‐pulse laser has been realized by employing a recently studied, self‐injection‐seeding pulse‐train generation scheme using Ce:LiCAF, a tunable ultraviolet laser medium. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115402

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A new type of ultrafast all optical switch based on a Mach–Zehnder interferometer is demonstrated with a 10 ps switching window which requires only 0.65 pJ of control pulse energy. The optical nonlinearity which is utilized is associated with the gain compression of semiconductor optical amplifiers, and the switching turnoff transition does not depend on the slow amplifier recovery time. Both data and control pulses are at the same wavelength of 1.313 &mgr;m, and are not polarized orthogonal to each other. The device configuration and the semiconductor amplifiers allow for small scale integration and data output cascadability. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115403

出版商:AIP    

年代:1995

数据来源: AIP