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Title: Doping of germanium and silicon crystals with non-hydrogenic acceptors for far infrared lasers

Abstract

A method for doping semiconductors used for far infrared lasers with non-hydrogenic acceptors having binding energies larger than the energy of the laser photons. Doping of germanium or silicon crystals with beryllium, zinc or copper. A far infrared laser comprising germanium crystals doped with double or triple acceptor dopants permitting the doped laser to be tuned continuously from 1 to 4 terahertz and to operate in continuous mode. A method for operating semiconductor hole population inversion lasers with a closed cycle refrigerator.

Inventors:
 [1];  [2]
  1. (Berkeley, CA)
  2. (Berlin, DE)
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA
OSTI Identifier:
872800
Patent Number(s):
US 6011810
Assignee:
Regents of University of California (Oakland, CA) LBNL
DOE Contract Number:
AC03-76SF00098
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
doping; germanium; silicon; crystals; non-hydrogenic; acceptors; infrared; lasers; method; semiconductors; binding; energies; larger; energy; laser; photons; beryllium; zinc; copper; comprising; doped; double; triple; acceptor; dopants; permitting; tuned; continuously; terahertz; operate; continuous; mode; operating; semiconductor; population; inversion; closed; cycle; refrigerator; silicon crystal; infrared laser; population inversion; closed cycle; binding energies; laser comprising; non-hydrogenic acceptors; crystals doped; infrared lasers; cycle refrigerator; doping semiconductor; doped laser; /372/257/

Citation Formats

Haller, Eugene E., and Brundermann, Erik. Doping of germanium and silicon crystals with non-hydrogenic acceptors for far infrared lasers. United States: N. p., 2000. Web.
Haller, Eugene E., & Brundermann, Erik. Doping of germanium and silicon crystals with non-hydrogenic acceptors for far infrared lasers. United States.
Haller, Eugene E., and Brundermann, Erik. Sat . "Doping of germanium and silicon crystals with non-hydrogenic acceptors for far infrared lasers". United States. doi:. https://www.osti.gov/servlets/purl/872800.
@article{osti_872800,
title = {Doping of germanium and silicon crystals with non-hydrogenic acceptors for far infrared lasers},
author = {Haller, Eugene E. and Brundermann, Erik},
abstractNote = {A method for doping semiconductors used for far infrared lasers with non-hydrogenic acceptors having binding energies larger than the energy of the laser photons. Doping of germanium or silicon crystals with beryllium, zinc or copper. A far infrared laser comprising germanium crystals doped with double or triple acceptor dopants permitting the doped laser to be tuned continuously from 1 to 4 terahertz and to operate in continuous mode. A method for operating semiconductor hole population inversion lasers with a closed cycle refrigerator.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Jan 01 00:00:00 EST 2000},
month = {Sat Jan 01 00:00:00 EST 2000}
}

Patent:

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  • A method for doping semiconductors used for far infrared lasers with non-hydrogenic acceptors having binding energies larger than the energy of the laser photons is disclosed. Doping of germanium or silicon crystals with beryllium, zinc or copper. A far infrared laser comprising germanium crystals doped with double or triple acceptor dopants permitting the doped laser to be tuned continuously from 1 to 4 terahertz and to operate in continuous mode. A method for operating semiconductor hole population inversion lasers with a closed cycle refrigerator is disclosed.
  • The optically pumped submillimeter wave lasers employing molecular gases having dipole moments are improved by employing as a polyatomic buffer gas a molecular gas or vapor of a hydrocarbon having a significantly large vibrational heat capacity in relation to its molecular weight. An example is C/sub 6/H/sub 14/ added to such lasers as the methyl fluoride laser at 496 micrometers. Other examples of saturated hydrocarbon buffers are also given; and in each case the vapor molecule is complex enough to absorb many vibrational quanta from the active molecules, yet is small enough to move rapidly to the tube walls.
  • We report for the first time on the use of high-temperature superconductor material for fabricating a resonator of a far-infrared solid-state laser. In our experiment the active medium consisted of a {ital p}-germanium crystal at 4.2 K in crossed electric and magnetic fields. We used a SrTiO{sub 3} plate as highly reflecting mirror and a YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin films on an MgO plate as output coupling mirror. We demonstrate highly reproducible operation of the laser.
  • We demonstrate operation of p-Ge far-infrared lasers with a planar contact geometry. The smallest laser crystal with this geometry has a maximum pulse length of 22 {mu}s, which is 10{percent} longer than the pulse length of comparably doped lasers with the traditional contact geometry. Calculations of the electric field distribution show that the fraction of active crystal volume for this new geometry is {approximately}four times larger than that of traditional geometries. Experiments and calculations reveal that in the planar design, the minimum applied voltage necessary for lasing decreases when the crystal geometry approaches a flat planar structure. This is duemore » to a significant increase of the total electric field caused by the Hall effect. {copyright} {ital 1999 American Institute of Physics.}« less
  • The authors have observed laser action in Al-doped germanium crystals with volumes as small as 0.03 cm{sup 3}, one order of magnitude smaller than previously studied p-Ge laser crystals. The duty cycle was increased by one order of magnitude. They improved the electric contacts and the cooling environment. Such progress marks a significant step toward continuous wave operation.