Efficient Laser-Pumped 10-micrometers Infrared Quantum Counter Upconversion in Rare Earth Doped Crystals: Materials and Phenomenon.
Abstract
From detailed theoretical considerations, it has been concluded that with Sm(3+) and Eu(3+) (or Sm(2+)) doped in soft single crystalline lattices and a strong optical laser pump, it is possible to achieve background-limited detection of 10-micrometers photons at 77K. It has been shown that in order to maximize the quantum efficiency of the upconversion process, it is necessary to minimize the multiphonon relaxation rates of the excited electronic states of the rare earth ions. Single crystals of SrCl2:Eu(3+) and SrCl2:Sm(3+):Eu(3+) (promising candidates as quantum counter crystals) have been grown by two different techniques. A new procedure has been developed for the oxidation of Sm(2+) to Sm(3+) in KCl in the preparation of quantum counter crystals such as KCl:Sm(3+):Sm(2+) and KCl:Sm(3+):Eu(3+). The quantum counter apparatus (consisting of a photon counting chamber, a CO2 laser, an argon ion laser, a dye laser, a mechanical chopper for phase-sensitive detection, and a PDP LAB 8 computer system) has been constructed and made fully operational. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 1971
- Accession Number
- AD0727182
Entities
People
- Francis K. Fong
Organizations
- Purdue University