Hole-coupled resonators for broadly tunable infrared free electron lasers

Ming Xie; Kwang Je Kim

doi:10.1117/12.150607

13 August 1993 Hole-coupled resonators for broadly tunable infrared free electron lasers

Ming Xie, Kwang Je Kim

Proceedings Volume 1868, Laser Resonators and Coherent Optics: Modeling, Technology, and Applications; (1993) https://doi.org/10.1117/12.150607
Event: OE/LASE'93: Optics, Electro-Optics, and Laser Applications in Scienceand Engineering, 1993, Los Angeles, CA, United States

Abstract

We review the study of hole-coupled resonators for broadly tunable free electron laser (FEL) applications. The mode profiles inside and outside the cavity, the diffraction losses at the mirror edges and intracavity apertures, the amount of useful power coupled through the holes, and the FEL gain are calculated for several dominant azimuthal and radial modes. The FEL interaction is taken into account by constructing a propagator similar to the Fresnel integral for free space propagation. It is found that non-confocal resonators can provide efficient hole coupling over a broad wavelength range, as long as the mode beating caused by a degeneracy in the round trip loss can be avoided. The degeneracy between the azimuthally symmetric class of modes is removed by FEL interaction, and the azimuthally asymmetric modes can be suppressed by means of intracavity apertures. Therefore, in a non-confocal configuration, a hole-coupled resonator can be designed that is tunable over a broad range of wavelength by employing an adjustable intracavity aperture. On the other hand, confocal resonators are not suitable for hole coupling; although mode beating does not occur in a confocal resonator, the hole coupling is difficult because the modes tend to avoid the hole. We provide a simple physical understanding of the difference in the performance of the confocal and non-confocal resonators. We also calculate and analyze the mode content of an empty resonator under continuous external mode injection. Such calculation is useful in interpreting experiments testing the hole coupling performance using CW lasers.

Citation Download Citation

Ming Xie and Kwang Je Kim "Hole-coupled resonators for broadly tunable infrared free electron lasers", Proc. SPIE 1868, Laser Resonators and Coherent Optics: Modeling, Technology, and Applications, (13 August 1993); https://doi.org/10.1117/12.150607

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available