Prc Inc.

Penn Research Corporation

Wayne M Penn

Frederick W Zur Burg

Donald B Griner

A method of zone refining a crystal wafer (116 FIG. 1) comprising the steps of focusing a laser beam to a small spot (120) of selectable size on the surface of the crystal wafer (116) to melt a spot on the crystal wafer, scanning the small laser beam spot back and forth across the surface of the crystal wafer (116) at a constant velocity, and moving the scanning laser beam across a predetermined zone of the surface of the crystal wafer (116) in a direction normal to the laser beam scanning direction and at a selectible velocity to melt and refine the entire crystal wafer (116).

Laser furnace and method for zone refining of semiconductor wafers

A forced transport, electrically excited molecular gas laser is disclosed. The laser includes a flow path for a gaseous lasing medium at high pressure such as 50 to 150 Torr, a blower for moving the gaseous lasing medium at high speed along the flow path, electrodes for electrically exciting the moving gaseous lasing medium along an active discharge length of the flow path to create a plasma for lasing, and an expansion chamber along the flow path in the vicinity of the active discharge length of the flow path for rapidly expanding the moving gaseous lasing medium to stir the plasma and provide a more uniform and stable discharge. The gas laser allows for high pressure and fast axial flow operation resulting in a compact design which produces high power optical output with uniform and stable mode characteristics.

Forced transport molecular gas laser and method

A gas laser tube assembly is disclosed wherein an elongated gas laser plasma tube is connected by a releasable connection to a member having a gas port positioned adjacent one end of the elongated gas laser plasma tube in spaced relationship thereto along the longitudinal axis of the plasma tube. The releasable connection and the member are arranged for telescoping movement with respect to another in either direction along the longitudinal axis of the plasma tube at least upon release of the connection thereby facilitating removal and installation of the plasma tube from the assembly. The releasable connection includes a first part connected to one end of the plasma tube and a second part releasably connected to the member with the first and second parts being releasably connected to one another. A cooling jacket surrounding the plasma tube is connected at one of its ends to the first part and an electrode is mounted on the second part and extends within the one end of the plasma tube whereby the electrode can be removed from the assembly for cleaning, repair or replacement without disturbing the integrity of the coolant passage defined between the cooling jacket and the plasma tube. Gas is conveyed to or from the plasma tube by way of the gas port in the member and cooperating gas passages in the releasable connection and the electrode.

Growing community of inventors

Cartersville, GA, United States of America

Wayne M Penn