摘要:

Continuous control of coherence length is realized in the output power region of 3–5 mW by changing the current flowing into the loss region of separately pumped (AlGa)As lasers. The controllable saturable absorption makes lasing spectra multimode and broadens the linewidth of an individual laser mode up to 2.5 A˚ through self‐pulsation. The threshold current of the laser is 60–80 mA. The lasing wavelength is around 780 nm.

ISSN:0003-6951    

DOI:10.1063/1.97442

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The transmission of a polymer film doped with dye molecules is modulated by voltage‐induced changes of the population in the center of a persistent spectral hole. It is demonstrated that the transmission versus voltage characteristic of the sample is adjustable to the requirements of the desired application by applying a selected time‐dependent voltage during spectral hole burning. Various characteristic curves have been tailor made and used for modulation and pulse forming of laser beams.

ISSN:0003-6951    

DOI:10.1063/1.97443

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The carrier density and light output of a pulse modulated GaAlAs diode laser were measured with picosecond time resolution. A new technique for measuring carrier density by transmission of picosecond light pulses through a diode laser is described. The measured carrier density was compared with a density calculated from the light output data using a rate equation analysis. Gain compression of a magnitude expected from relaxation oscillation damping rates was observed. Because the experiment measures the density at the center of the waveguide, and not the average across the active layer, the compression mechanism is not spatial hole burning.

ISSN:0003-6951    

DOI:10.1063/1.97444

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Surface‐emitting GaAlAs/GaAs linear laser arrays are fabricated using the ion milling technique. Low threshold current and differential quantum efficiency comparable to these of the cleaved device are obtained.

ISSN:0003-6951    

DOI:10.1063/1.97445

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We present the first demonstration of a room‐temperature grating fixing process in a photorefractive Bi12SiO20crystal. This arises from a space‐charge compensation due to a hole conduction when the crystal is placed in the dark for 1–3 min. The grating is optically revealed by redistribution of photoelectrons through the uniform illumination of the crystal. After compensation and optical revelation, the readout time constant of the grating is increased by a factor of 40×. Electrical revelation of fixed gratings and holographic images is also demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.97446

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Experiments have been carried out to investigate a new method for generating O2(1&Dgr;) with long‐time operation of an efficient chemical oxygen‐iodine laser system in mind. An impinging‐jet nozzle was utilized to atomize a H2O2‐KOH solution so that the alkaline H2O2/Cl2reaction might occur in droplet‐gas phase with high excitation efficiency. Experimental results indicate that the present generator can yield as high as 80% of O2(1&Dgr;) with reasonable O2flow rate.

ISSN:0003-6951    

DOI:10.1063/1.97447

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We describe a GaAlAs/GaAs distributed feedback (DFB) laser with double channel planar buried heterostructure operating at &lgr;=0.88 &mgr;m. The device has been prepared using three‐step liquid phase epitaxy. A cw threshold current as low as 12 mA at room temperature has been accomplished even with third‐order diffraction gratings. A single longitudinal mode oscillation without mode hopping has been observed at any injection level over a temperature range of 60 K. These characteristics are indeed almost comparable to the well‐developed quaternary counterparts, thus showing that the excellent spectral purity of DFB lasers will soon be available in the fields where shorter wavelengths are needed.

ISSN:0003-6951    

DOI:10.1063/1.97448

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We describe aV‐groove distributed feedback laser operating at &lgr;=1.5 &mgr;m. A second‐order diffraction grating has been defined by electron beam writing and transferred using ion beam milling after the crystal growth was completed. A single longitudinal mode operation with a mode rejection ratio larger than 5000:1 has been obtained under modulation rate of 1 GHz. The techniques used in this work can be applied to other types of buried heterostructure lasers.

ISSN:0003-6951    

DOI:10.1063/1.97449

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The attenuation of far‐infrared (&lgr;=0.119 mm) surface plasmons has been measured as a function of the thickness of a silicon overlayer on top of silver. Good agreement with theory was obtained indicating that the Dru¨de model for the dielectric constant of silver is valid out to these wavelengths.

ISSN:0003-6951    

DOI:10.1063/1.97450

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

In this letter we analyze an induced resonance electron cyclotron (IREC) quasi‐optical maser configuration, which has the unique features of being highly efficient and, with the proper choice for the index of refraction, relatively insensitive to the electron beam’s energy spread. The radiation mechanism can, however, be sensitive to the beam’s pitch angle spread. A system of nonlinear coupled orbit equations, describing the dynamics of electrons in a spatially varying magnetic field, and the electromagnetic field of a steady‐state open resonator configuration are derived and analyzed. Furthermore, we show that by appropriately tapering the magnetic field an induced resonance condition can be achieved which results in high interaction efficiencies. It is anticipated that an efficient, high power millimeter, submillimeter, and infrared radiation source can be realized with the IREC quasi‐optical maser configuration.

ISSN:0003-6951    

DOI:10.1063/1.97451

出版商:AIP    

年代:1986

数据来源: AIP