摘要:

Output energies of 15 mJ/pulse and peak powers of 100 kW/pulse are obtained from a 4.3‐&mgr;m CO2laser which is optically pumped by a 10‐&mgr;m sequence‐band CO2laser. The dominant operating characteristics of the laser and their effect on output energy, line tunability, and scalability are discussed.

ISSN:0003-6951    

DOI:10.1063/1.95427

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

New buried optical waveguides whose refractive index profiles can be controlled by rediffusion are formed by the ion exchange and rf sputtering technique. A buried waveguide with a nearly symmetric refractive index distribution and a new slowly tapered structure are fabricated.

ISSN:0003-6951    

DOI:10.1063/1.95428

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Stable transverse mode operation has been realized for the first time in visible (780 nm) multiquantum well lasers composed of seven 3‐nm‐thick GaAs wells separated by six 5‐nm‐thick Ga0.8Al0.2As barriers grown by metalorganic chemical vapor deposition. A self‐aligned structure with a built‐in optical waveguide to stabilize the transverse mode is fabricated by a two‐step epitaxial technique. Low threshold current (35 mA), high output power (up to 40 mW) in the fundamental transverse mode, and a very low degradation rate at 70 °C have been confirmed.

ISSN:0003-6951    

DOI:10.1063/1.95429

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Precise observation of the single longitudinal mode spectrum for distributed feeedback lasers revealed fine structures when the spectrum was broadened by high‐speed modulation. A dynamic simulation can explain reasonably the above behavior if the model takes into account the carrier density modulation enhanced by the relaxation oscillation. In this letter, experimental results where both modulation depth and speed were varied are described along with a calculated result.

ISSN:0003-6951    

DOI:10.1063/1.95430

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Visible light generation by sum‐frequency mixings in a polarization‐preserving fiber has been observed with pumping by a 1.064‐&mgr;mQ‐switched, and mode‐locked neodymium:yttrium aluminum garnet laser. The visible light has been efficiently generated when the fast axis of the test fiber was excited. The total conversion efficiency from the pump to all visible wavelengths amounts to 1% with a mode‐locked pump peak power of 18 kW. By fusion splicing two fibers with different visible emission lines, we have succeeded in combining those two visible spectra into one spectrum.

ISSN:0003-6951    

DOI:10.1063/1.95431

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

NH3absorption lines due to vibration‐rotation transitions are observed at 1.50–1.54 &mgr;m by using an InGaAsP superluminescent diode. A 1.5‐&mgr;m InGaAsP distributed feedback (DFB) laser is frequency stabilized to an NH3linear absorption line at 15196 A˚. Frequency stability of &sgr;(2,&tgr;)=8×10−11&tgr;−1is achieved for an averaging time range of 10 ms≤&tgr;≤1 s. Such an absolute frequency‐stabilized DFB laser is useful for coherent optical system applications, since it is free from the longitudinal mode jumping which results from a wide range of temperature changes and long‐term device degradation.

ISSN:0003-6951    

DOI:10.1063/1.95432

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A quantitative theory for the optical properties of crystalline electrochromic materials is introduced. It is based on the double injection model and includes ionized impurity scattering of free electrons. Solar and luminous properties are evaluated versus electron density for doped WO3films. Our results point to the possibility of creating efficient ‘‘smart windows’’ with dynamic control of the inflow of radiant energy.

ISSN:0003-6951    

DOI:10.1063/1.95415

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Competition between external beam amplification and normal laser action is shown to result in a new type of optical bistability in high gain lasers. With one dye laser in a delayed self‐extinction configuration, periodic pulsations are observed, showing the alternation of two quasi‐stable states. With a twin dye laser configuration, only one laser at a time could be above threshold due to their mutual coupling. Switching with subnanosecond rise time has been obtained in a purely optical way.

ISSN:0003-6951    

DOI:10.1063/1.95416

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

An eight‐element phase‐locked array of index‐guided separate confinement ridge AlGaAs diode lasers is fabricated. In this array the absorption of light in the region between lasers is negligible and the gain profile across the array is nearly uniform. Unlike most other arrays, this array oscillates in its fundamental mode. Stable radiation patterns of near diffraction‐limited single narrow beam with 1.6° width are obtained. The beam width approaches the theoretical limit for the present array structure.

ISSN:0003-6951    

DOI:10.1063/1.95417

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Measurements of the carrier induced refractive index change in AlGaAs quantum well lasers are presented which show that the guided mode in single quantum well lasers exhibits a small (&Dgr;n/&Dgr;N∼−3×10−22cm3) carrier induced change in refractive index. This is more than an order of magnitude smaller than the corresponding value for conventional active layer lasers. The measured &Dgr;nA/&Dgr;N∼−7×10−21cm3in the active layers of AlGaAs multiquantum well structures. The measured index changes of the guided mode at threshold (&Dgr;nth) are −5.6×10−3and −7.6×10−3for the single quantum well and multiquantum well lasers, respectively. This should be compared with a value of ∼1.2×10−2for conventional active layer lasers. These results suggest that single frequency sources fabricated using real index guided single quantum well active layers may have improved frequency stability under direct current modulation.

ISSN:0003-6951    

DOI:10.1063/1.95418

出版商:AIP    

年代:1984

数据来源: AIP