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Showing papers on "Quantum well published in 1976"


Journal ArticleDOI
M. B. Panish1
01 Oct 1976
TL;DR: In this article, the authors considered configurations of uniformly pumped semiconductor slabs that constitute the transmission medium of multilayered slab waveguides, whose boundaries are trapless heterojunctions.
Abstract: A state-of-the-art discussion of heterostructure injection lasers is presented. These lasers are first considered as configurations of uniformly pumped semiconductor slabs that constitute the transmission medium of multilayered slab waveguides, whose boundaries are trapless heterojunctions. Emphasis is on lasers whose electrically active and waveguiding layers are Al x Ga 1-x As or GaAs, although several other semiconductors are discussed. Single, double, and separate confinement hetrostructure lasers, all of which yield carrier and optical confinement normal to the plane of the heterojunctions, are described. Lateral electrical and optical confinement in various stripe geometry double-hetrostructure lasers is illustrated. In addition to the more common Fabry-Perot cavity lasers, there are now also several new varieties that use corrugated surfaces as Bragg gratings for internal distributed feedback or reflection. Some of these heterostructure lasers have permitted the demonstration of CW-room temperature injection lasers with low threshold current densities ( 105) h), and a considerable degree of control over modes and beam divergence. In addition, the use of heterostructures has permitted the demonstration of the first integratedoptical structures that include both active light generating and passive elements on a single chip.

76 citations


Journal ArticleDOI
TL;DR: In this article, the laser oscillation in injection-pumped GaAs•Ga1−xAlxAs double-heterostructure distributed Bragg reflector (DBR) lasers is reported.
Abstract: Laser oscillation in injection‐pumped GaAs‐Ga1−xAlxAs double‐heterostructure distributed Bragg reflector (DBR) lasers is reported. Current threshold density as low as 890 A/cm2 in pulsed operation has been obtained at 183 °K. In this laser diode, the corrugations are placed outside the active part of the laser in the form of an end pair of parallel Bragg reflectors. The observed characteristics of the DBR lasers are found to agree well with the theory.

57 citations


Patent
03 Mar 1976
TL;DR: In this paper, a plurality of pulsed chemical lasers are disposed symmetrically about a central axis, and each laser is energized sequentially so that the resulting output laser pulses have substantially consecutive time duration.
Abstract: A plurality of pulsed chemical lasers such as HF or DF lasers are disposed symmetrically about a central axis. Each laser is energized sequentially so that the resulting output laser pulses have substantially consecutive time duration. Hence, the duration of the laser pulses equals the duration of each laser times the number of lasers. Reflectors are provided for combining the output pulses of each laser to generate a segmented output beam.

11 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present a theory that explains long time delays in GaAs junction lasers, based only on processes known to occur in these lasers, and show that Q-switching and related phenomena can be explained.
Abstract: We present a theory that explains long time delays. Q-switching and related phenomena in GaAs junction lasers, based only on processes known to occur in these lasers.

7 citations


Journal ArticleDOI
TL;DR: In this article, an equation derived for the integrated gain coefficient is used to explain the shortening mechanism in the long pulse stage in which gain saturation is shown to have an emphasized role in the compression of the trailing edge.
Abstract: Passive mode locking of dye lasers is studied with the inclusion of the relaxation times. An equation derived for the integrated gain coefficient is used to explain the shortening mechanism in the long pulse stage in which gain saturation is shown to have an emphasized role in the compression of the trailing edge.

5 citations


Journal ArticleDOI
TL;DR: CW room-temperature injection lasers compare favorably with low-power gas lasers in many optical information han-dling applications as discussed by the authors. But their performance is not as good as low power gas lasers.
Abstract: CW room-temperature injection lasers compare favorably with low-power gas lasers in many optical information han-dling applications.

2 citations




Journal ArticleDOI
TL;DR: In this paper, a theoretical analysis is made of the dependence of the width and contrast of power resonances in ring gas lasers on the parameters of the amplifying and absorbing media present in these lasers.
Abstract: A theoretical analysis is made of the dependence of the width and contrast of power resonances in ring gas lasers on the parameters of the amplifying and absorbing media present in these lasers. It is shown that the instability of the frequency standards utilizing ring and linear lasers is due to different factors: in ring lasers the most important are the fluctuations of the parameters of the amplifying medium, whereas in linear lasers the technical fluctuations of the resonator length are dominant.