摘要:

The observation of persistent spectral hole burning (PSHB) in Eu3+‐doped aluminosilicate glass at 77 K is reported in this letter. The homogeneous linewidth of the7F0→ 5D0transition is measured to be ∼0.5 A˚ by both PSHB and fluorescence line narrowing techniques. The ratio of inhomogeneous‐to‐hole widths at 77 K is 45. The7F0→ 5D0transition is visible directly in transmission due to the high concentration of Eu3+. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115740

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The high power operation of mid‐infrared quantum cascade lasers at temperatures up toT=320 K is reported. Gain at high temperature is optimized by a design combining low doping, a funnel injector, and a three‐well vertical transition active region. A molecular beam epitaxy grown InP top cladding layer is also used to optimize heat dissipation. A peak pulsed optical power of 200 mW and an average power of 6 mW are obtained at 300 K and at a wavelength &lgr;=5.2 &mgr;m. The devices also operate in continuous wave up to 140 K. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115741

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Quasi‐phase matched (QPM) surface emitting second harmonic generation was demonstrated with nonlinear/linear multilayer waveguides in poled polymer based devices. The nonlinear/linear multilayer film was fabricated with a 4‐dimethylamino‐4′‐nitrostilbene (DANS) side chain polymer and a cross‐linkable clear polymer. Large efficiency improvement was observed with a combination of QPM and strong field parallel poling. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115742

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Nonlinear optical limiting behavior of carbon 60 (C60), platinum poly‐yne (PPY), and tetrabenzporphyrin (TBP) was evaluated using lasers with &mgr;s and ns pulse widths at the wavelength of 750 nm in anf/5 optical setup. PPY had the lowest clamping level for ns pulses, and TBP had the lowest clamping level for &mgr;s pulses. Possible explanations for nonlinear optical behavior are provided. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115743

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We report an experimental and theoretical analysis of the threshold properties of infrared oxide‐confined vertical‐cavity surface emitting lasers. We find good agreement between experiment and theory on the wavelength dependencies of the threshold current density and intrinsic voltage. The threshold voltage is shown to equal the sum of the calculated quasi‐Fermi energy separation and the ohmic drop arising from a record low 17 to 30 &OHgr; series resistance in these vertical‐cavity lasers. Our analysis provides two independent means for determining the material threshold gain. A threshold gain of 500 cm−1is found for these oxide‐confined lasers, which is half that estimated for ion‐implanted lasers with inferior electrical and optical confinement. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115744

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We report the demonstration of an infrared avalanche photodetector that uses an InGaAs absorption layer and a Si avalanche multiplication layer bonded by wafer fusion. Photocurrent measurements of the silicon heterointerface photodetector showed high response to 1.3 &mgr;m light and gains of up to 130. Frequency response measurements for the detectors yielded 3 dB bandwidth products of up to 81 GHz. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115975

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Green light was generated by second harmonic generation in LiTaO3thin films grown on sapphire. We describe the optical properties of the thin films grown by rf magnetron sputtering. We report on the experimental conditions for second harmonic generation by modal dispersion and quasi phase matching. For quasi phase matching, proton exchange was used to periodically deaden the nonlinearity of the crystal. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115976

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

An experimental study of the combination of four‐wave mixing and current modulation in a semiconductor optical amplifier is presented. The measurement of the small signal chirp parameter for the conjugate signal is performed giving results between 0 and −1 for all detuning below 1.5 THz. Its value is much smaller than that of the directly modulated amplifier and furthermore is negative. A conjugate pulse traveling along a standard fiber exhibits no noticeable broadening. The results are in very good agreement with the theory developed in the literature. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115977

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Reactive dc magnetron sputtering was used to make mixed Ti–Ce oxide films with a Ce/Ti ratio &ggr; between 0 and 0.6. Their optical and electrochemical properties were strongly dependent on the composition. Films with 0.3<&ggr;<0.6 were optically passive under charge insertion, which makes them suitable as counterelectrodes in transparent electrochromic devices. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115978

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We propose a quantum structure of AlGaAs lasers designed for high‐temperature operation. In this design, the superlattice structure multiple‐quantum barrier (MQB) is located in the middle of active region which improves the injection efficiency of holes from the cladding into the active region, compared to MQB in cladding structure. Simulation results showed that low energy electrons can tunnel through the MQB barriers, while high energy electrons were reflected back by effective potential barrier to suppress the electron overflow from active to the cladding region. Multiple‐quantum wells (MQWs) are integrated at each side of MQB to minimize the overflow of tunneled electrons. A differential quantum efficiency change as small as 5% was achieved in the temperature range of 20–100 °C from MQB+MQW in active lasers. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115979

出版商:AIP    

年代:1996

数据来源: AIP