Terahertz gyrotrons with quasi-regular cavities
We describe two ways of the use in high-harmonic gyrotrons of quasi-regular cavities with short irregularities formed by the widening of cavity radius. The first one is a significant improvement of the selectivity of the second-harmonic gyrotrons due to the supression of parasitic near-cutoff fundamental-harmonic waves. The second approach is aimed to solve a typical problem of weakly-relativistic high-harmonics gyrotrons, namely, the use of long cavities ensuring extremely high diffraction Q-factors and a great share of Ohmic losses. We propose a quasi-regular cavity with periodic phase correctors, where a far-from-cutoff axial mode with a decreased diffraction Q-factor is excited in a gyrotron-like regime.
Sub-THz gyrotrons with special functions of frequency control for applications to DNP-NMR spectroscopy
Sub-THz gyrotrons with the functions of frequency control are useful for application to high power sub-THz spectroscopy including a DNP enhanced high-sensitive NMR spectroscopy. Continuous frequency tunability, frequency modulation and frequency step-changing will be achieved for our Gyrotron FU CW Series and such special functions of frequency control are applied for additional enhancement of NMR sensitivity. In this paper, it will be presented how such functions are achieved and how about the advantages of them for sensitivity enhancement of NMR spectroscopy.
Strategies for glass based photonic system integration
There is a clear tendency to integrate more and more opto-electronic and micro-optical components like optical fibers, laser diodes, modulators, isolators, beam-splitting components and micro lenses in also increasingly dense and complex assemblies. The paper will discuss thin glass as a very promising base material for that kind of photonic packaging on interposer and board level including optical interconnection using fibers.