Radiation sources based on semiconductor devices for multichannel THz-IR spectroscopy Текст научной статьи по специальности «Медицинские технологии»

THz-I-14

Radiation sources based on semiconductor devices for multichannel THz-IR spectroscopy

V. Vaks1, V. Anvertev1, M. Chernyaeva1, E. Domracheva1, S. Pripolzin1

institute for Physics of Microstructures RAS, Terahertz spectrometry, Nizhny Novgorod,

Russian Federation

Actual problems in the gas analysis are associated with developing the methods of analysis of multicomponent gas mixtures for various applications.

The special consideration is given to improving the sensitivity of spectroscopic analysis owing combining the terahertz spectral approach with IR quantum cascade lasers (QCL).

The main problem of high precise spectroscopy is development of high-stable tunable coherent radiation sources. The modern spectroscopic requirements to THz radiation sources are frequency stabilization with accuracy ~10-8 -10-10 from carrier frequency, high spectral purity and smooth tuning of frequency in wide frequency range.

The development of semiconductor technology will open the new horizon in realization of the radiation sources and detectors for terahertz spectroscopy. Developing the semiconductor devices being combined radiation sources for different frequency ranges may be a new direction of devices design.

The review of modern semiconductor radiation sources of THz and IR ranges is presented.

QCLs operating in continuous and pulse modes are used for IR range. The various approaches to IR QCL frequency stabilization (superheterodyne method, Pound-Drever-Hall method, stabilization at the frequency of gas absorption line) were considered.

The development of THz emitters based on QCL up to 3-4 THz is presented. The possibility of frequency multiplying the frequency of QCL for the developing the inaccessible part of THz range over 5 THz is considered. The multiplier based on semiconductor superlattices (SL) operated from 0.1 to 10 THz will be used.

Elaboration of new semiconductor radiation sources allow developing the multichannel THz-IR nonstationary spectroscopy for fast qualitative and quantitative analysis of some substances, which can be important for various applications. Such substances are, e.g., metabolites concerned with cancer disease for its early diagnostics.

The authors acknowledge the support from Presidium RAS Program No. 5: "Photonic technologies in probing inhomogeneous media and biological objects"