摘要:

Stable thin films of zirconium dioxide are produced by ion‐assisted electron beam deposition at room temperature and 300 °C. The method yields films with substantially increased packing density resulting in refractive indices close to the bulk value. The improvement in optical properties is accompanied by an amorphous to cubic crystalline transition of the film structure which is mixed with a monoclinic phase for heated films.

ISSN:0003-6951    

DOI:10.1063/1.94485

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

When an extremely short optical pulse is focused into an electro‐optic material, a moving polarization is produced which radiates in a Cerenkov‐like cone. At the boundary of this shock wave, the electric field consists of an extremely fast electrical transient with a correspondingly wide spectral distribution extending well into the far infrared. When appropriately coupled out of the material, this shock wave can be used as a fast electronic impulse generator or far‐infrared source without requiring subminiature transmission structures to guide the signal.

ISSN:0003-6951    

DOI:10.1063/1.94486

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Widely tunable single‐mode picosecond pulses have been obtained from a buried optical guide AlGaAs semiconductor laser operated with external grating feedback. Intensity autocorrelation measurements show single‐mode 30‐ps pulses. A tuning range of 20 nm, corresponding to more than 70 different laser frequencies, was easily achieved.

ISSN:0003-6951    

DOI:10.1063/1.94487

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

The direct etching of polyethylene terephthalate film using a XeCl laser has been investigated and is shown to be consistent with a thermal model for degradation. Microstructure revealed by deep etching suggests the UV laser may prove useful for studying polymeric materials. Polyimide and photoresist film has also been directly etched.

ISSN:0003-6951    

DOI:10.1063/1.94488

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

A novel method for real‐time measurement of ultrashort optical pulses generated from InGaAsP diode lasers at the wavelength of 1.3 &mgr;m has been realized by means of an ultrafast streak camera incorporating a frequency up‐conversion technique with a LiIO3crystal pumped by aQ‐switched neodymium: yttrium aluminum garnet (Nd:YAG) laser at 1.064 &mgr;m. The optical pulse from an InGaAsP double‐channel planar buried heterostructure (DC‐PBH) diode laser operated by a short pulse current of 1‐ns duration was measured to have a full width at half‐maximum (FWHM) of approximately 28 ps by single shot scanning with the temporal resolution of 8 ps. Using a 15‐mm‐long LiIO3crystal and 500‐W peak power of the pumping laser pulse focused at 400 &mgr;m in diameter, the up‐conversion efficiency and minimum detectable peak power of the diode laser pulse at 1.3 &mgr;m were estimated to be approximately 0.65% and 1 mW, respectively. This technique can be widely utilized for real‐time detection of ultrashort optical pulses in the wavelength range beyond 1–10 &mgr;m or more.

ISSN:0003-6951    

DOI:10.1063/1.94489

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Single longitudinal mode operation of cleaved‐coupled‐cavity lasers formed by recleaving of 1.5‐&mgr;m InGaAsP buried crescent lasers is investigated as a function of bias current, temperature, and modulation frequency. The two‐cavity lasers are made to operate in a stable single mode by adjusting the bias levels of the electrically isolated and optically coupled sections. The wavelength stability with temperature results in a change of only 0.48 A˚/°C over a range of 14 °C. Single mode operation is preserved under direct modulation at rates as high as 1 Gb/s. The reduction in linewidth and the absence of partition noise makes these lasers useful for optical transmission through highly dispersive single mode fibers.

ISSN:0003-6951    

DOI:10.1063/1.94490

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

We describe the design and preliminary performance characteristics of a compact sealed, transverse rf discharge excited waveguide CO2laser which is capable of output powers of 30 W and a peak efficiency of 13% from a 37‐cm discharge length.

ISSN:0003-6951    

DOI:10.1063/1.94491

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

The phonon assisted gain coefficient is evaluated theoretically for AlGaAs quantum well lasers by means of a renormalization theory. It is clarified that the phonon assisted gain coefficient saturates strongly with respect to the phonon number. Its maximum value is smaller than the corresponding gain coefficient of the direct transition. The wavelength, where the phonon assisted gain coefficient is maximum, approaches the direct transition wavelength as the pump rate increases.

ISSN:0003-6951    

DOI:10.1063/1.94492

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

This study demonstrates that pulsed laser illumination may be used to suppress the ambient motion related instabilities associated with the application of coherent multimode optical fiber image bundles to the recording of remote holograms.

ISSN:0003-6951    

DOI:10.1063/1.94476

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Stress compensation in GaAs‐(Ga,Al)As laser diodes is discussed. The stress distributions in the laser diodes are theoretically simulated by the finite element method. The photoelastic effect is used to observe the actual strain fields. It is found by simulation that the stress can be minimized by optimizing the Si submount thickness. Lasers fabricated with the optimized submount successfully exhibit low strain fields.

ISSN:0003-6951    

DOI:10.1063/1.94477

出版商:AIP    

年代:1983

数据来源: AIP