Search

The spatial and spectral emission characteristics of a two-dimensional CdS laser array, pumped by a high-energy electron beam, have been experimentally investigated. The near-field emission from each cell or array element is found to arise from a virtual line located behind the cell. The results are consistent with a geometric ray model of a tilted mirror resonator. [ABSTRACT FROM AUTHOR]

We have observed cw laser action on a new transition (4D3/2→4I11/2) of the Nd3+ ion at 380 nm. This was demonstrated in Nd:LaF3 using an upconversion pumping scheme in which near infrared (788 nm) and visible (591 nm) pump photons from cw dye lasers produce stepwise excitation of the Nd3+ ion. In addition, lasing was observed with a single pump source at wavelengths around 578 nm using doubly resonant, sequential absorption of two yellow photons. Single-mode, cw operation with an output power of 12 mW was measured at 20 K with 1% output coupling and pump powers of several hundred mW. At 77 K the maximum power dropped to 4 mW. [ABSTRACT FROM AUTHOR]

We report on an efficient semiconductor laser array pumped by a high-energy electron gun. A peak power of 350 kW in a 4-ns pulse has been measured from a 25-mm2 CdS laser. For the materials studied (CdS, ZnxCd1-xS, and ZnSxSe1-x), laser action has been obtained in the blue-green region of the spectrum. [ABSTRACT FROM AUTHOR]

The magnetic and transport behaviors of epitaxial Ge1-xFexTe thin film with low Fe concentration (x = 0.02) deposited by pulsed laser deposition have been investigated. Temperature-dependent magnetization and anomalous Hall effect result in a Curie temperature of ∼160 K. A high hole density resulting from crystalline defects induces a long-range ferromagnetism. Competition between spontaneous magnetization and thermal effects leads to a change of magnetoresistance ratio from positive to negative with increasing temperature. The minimum carrier concentration is achieved at 160 K, which may correspond to ferromagnetic-paramagnetic phase transition, implying that ferromagnetism is closely related to transport behaviors. [ABSTRACT FROM AUTHOR]