TY - JOUR

T1 - Operation regimes of Cerenkov-Smith-Purcell free electron lasers and T.W. amplifiers

AU - Gover, Avraham

AU - Livni, Zohar

N1 - Funding Information:
There has been recently considerable theoretical and experimental interest in the concept of free electron lasers \[1-11 \]. Laser anlplification at 10.6/ira wavelength \[2\]a nd laser oscillation at 3.4 ~m \[3\], were demonstrated using "magnetic bremsstrahlung" radiation scheme, proving that coherent stimulated emission from accelerated free electrons is possible at optical frequencies. Free electron lasers based on the Smith-Purcell effect \[12\] or Cerenkov radiation have been suggested \[4,9\].S uch free electron lasers if realized could be made with much more compact device structures compared to the bremsstrahlung laser, and therefore may be interesting for applications. A gain expression for the Smith-Purcell-Cerenkov free electron laser was derived in ref. \[4\] where it was shown that at the single electron interaction regime the exponential gain is proportional to the electron density n O and to the derivative of the electron beam distribution function at velocity corresponding to the phase velocity (co/t3) of the amplified electromagnetic wave -f\[i(v)lv = co/15, co and ~ are the angular frequency and the wavenumber of the electromagnetic wave respectively. It was also shown there that in the collective interaction regime the dispersion equation of the free electron laser reduces to that of the conventional T.W. amplifier \[13\].I n ref. \[14\] the Cerenkov * This research is supported by the Air Force Office of Scien-tific Research under grant No. AFOSR-77-3445.

PY - 1978/9

Y1 - 1978/9

N2 - We present a unified linear analysis which describes free electron lasers based on Cerenkov and Smith-Purcell effects and T.W. amplifiers. In the single electron interaction regime the analysis reproduces the exponential and non exponential (interferential) gain expressions. It is shown that the first expression is dominant and that considerable increase in the gain can be attained by using electron beams with small velocity spread.

AB - We present a unified linear analysis which describes free electron lasers based on Cerenkov and Smith-Purcell effects and T.W. amplifiers. In the single electron interaction regime the analysis reproduces the exponential and non exponential (interferential) gain expressions. It is shown that the first expression is dominant and that considerable increase in the gain can be attained by using electron beams with small velocity spread.

UR - http://www.scopus.com/inward/record.url?scp=0018011128&partnerID=8YFLogxK

U2 - 10.1016/0030-4018(78)90226-2

DO - 10.1016/0030-4018(78)90226-2

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AN - SCOPUS:0018011128

SN - 0030-4018

VL - 26

SP - 375

EP - 380

JO - Optics Communications

JF - Optics Communications

IS - 3

ER -