Embedded-mirror semiconductor laser

Abstract

Data are presented demonstrating the operation of a current-injection laser diode with embedded reflectors instead of etched or cleaved facets. The laser structure, grown by molecular beam epitaxy, uses AlAs-GaAs superlattices SL’s in place of conventional AlxGa1−xAs cladding layers. The sample is patterned, etched, and Zn diffused to selectively disorder the SL cladding layers producing a ∼200×∼100 μm rectangular laser cavity embedded in the surrounding AlxGa1−xAs. Following Si3N4 deposition and metallization, the diodes are cut (not cleaved) with intentionally damaged edges. These devices operate as lasers (77 K, pulsed operation) with a mode spacing corresponding to either the ∼100-μm or the ∼200-μm cavity length formed by the selective interdiffusion of the SL cladding layer. This embedded-mirror laser structure may be useful in the development of optical integrated circuits by allowing semiconductor lasers to be monolithically integrated with other optical devices.

Multireference perturbation theory with optimized partitioning. I. Theoretical and computational aspects

“…͑2.11͒ was proposed by Laidig, Saxe, and Bartlett. 24,25 They start from the exponential ansatz for a CASSCF wave function…”

“…10,11 The equations defining MROPT͑2͒ are also identical to those for the linearized multireference coupled cluster method proposed by Laidig, Saxe, and Bartlett. 24,25 The present paper gives a general theory of the MROPT method. We also give here discussion of theoretical and computational aspects of the second-order MROPT͑2͒ method, such as size-consistency, orbital dependence, and a comparison of total MROPT͑2͒ energies with those obtained using other related methods.…”