Conversion of heat to light using Townes' maser-laser engine: Quantum optics and thermodynamic analysis

Journal Article · Fri Apr 15 00:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.043838· OSTI ID:21544724

Ooi, C H. Raymond ^[1]

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1. Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

It is shown that thermal energy from a heat source can be converted to useful work in the form of maser-laser light by using a combination of a Stern-Gerlach device and stimulated emissions of excited particles in a maser-laser cavity. We analyze the populations of atoms or quantum dots exiting the cavity, the photon statistics, and the internal entropy as a function of atomic transit time, using the quantum theory of masers and lasers. The power of the laser light is estimated to be sufficiently high for device applications. The thermodynamics of the heat converter is analyzed as a heat engine operating between two reservoirs of different temperature but is generalized to include the change of internal quantum states. The von Neumann entropies for the internal degree are obtained. The sum of the internal and external entropies increases after each cycle and the second law is not violated, even if the photon entropy due to finite photon number distribution is not included. An expression for efficiency relating to the Carnot efficiency is obtained. We resolve the subtle paradox on the reduction of the internal entropy with regards to the path separation after the Stern-Gerlach device.

• OSTI ID: 21544724
• Journal Information: Physical Review. A, Vol. 83, Issue 4; Other Information: DOI: 10.1103/PhysRevA.83.043838; (c) 2011 American Institute of Physics; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ATOMS
CONVERSION
EFFICIENCY
ENTROPY
HEAT ENGINES
HEAT SOURCES
LASER CAVITIES
LASERS
MASERS
OPTICS
PHOTONS
QUANTUM DOTS
QUANTUM STATES
STERN-GERLACH EXPERIMENT
STIMULATED EMISSION
THERMODYNAMICS
VISIBLE RADIATION
AMPLIFIERS
BOSONS
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
ELEMENTARY PARTICLES
EMISSION
ENERGY-LEVEL TRANSITIONS
ENGINES
EQUIPMENT
MASSLESS PARTICLES
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
NANOSTRUCTURES
PHYSICAL PROPERTIES
RADIATIONS
THERMODYNAMIC PROPERTIES