TY - JOUR

T1 - Experimental researches of acoustical modes of various types of resonant photo-acoustic detectors

AU - Sherstov, Igor

AU - Chetvergova, Lyana

PY - 2020/5/1

Y1 - 2020/5/1

N2 - An experimental study of acoustic modes of resonant photo-acoustic detectors (PAD) of various types has been carried out. It is shown that ring longitudinal modes are formed in resonant differential PADs (Miklos's and Kapitanov's schemes) with two parallel acoustic resonators that protrude from the acoustic resonators of the detector into the buffer cavities for a short distance (∼1–2 mm) and do not reach the flanges (windows) of the PAD. This property of the ring longitudinal acoustic modes of differential PADs significantly reduces the sensitivity of the detectors to the parasitic effect of background absorption by the detector windows. The optimal length of the buffer cavities of the differential PAD is comparable to the diameter of the acoustic resonators of this detector (∼10 mm). It was also experimentally shown that in the longitudinal resonant PAD (Harren's scheme) only longitudinal acoustic modes are formed along the entire length of the detector, in which the antinodes of pressure oscillations of the standing sound wave in resonance are located on the flanges (windows) of the buffer cavities, which reduces the noise immunity of this detector to the effect of background absorption in windows as compared to the ring modes of the differential resonant PAD.

AB - An experimental study of acoustic modes of resonant photo-acoustic detectors (PAD) of various types has been carried out. It is shown that ring longitudinal modes are formed in resonant differential PADs (Miklos's and Kapitanov's schemes) with two parallel acoustic resonators that protrude from the acoustic resonators of the detector into the buffer cavities for a short distance (∼1–2 mm) and do not reach the flanges (windows) of the PAD. This property of the ring longitudinal acoustic modes of differential PADs significantly reduces the sensitivity of the detectors to the parasitic effect of background absorption by the detector windows. The optimal length of the buffer cavities of the differential PAD is comparable to the diameter of the acoustic resonators of this detector (∼10 mm). It was also experimentally shown that in the longitudinal resonant PAD (Harren's scheme) only longitudinal acoustic modes are formed along the entire length of the detector, in which the antinodes of pressure oscillations of the standing sound wave in resonance are located on the flanges (windows) of the buffer cavities, which reduces the noise immunity of this detector to the effect of background absorption in windows as compared to the ring modes of the differential resonant PAD.

KW - Helmholtz differential resonator

KW - Resonant differential photo-acoustic detector

KW - Ring longitudinal acoustic modes

KW - SPECTROMETER

KW - GAS-ANALYSIS

KW - SPECTROSCOPY

KW - CELL

UR - http://www.scopus.com/inward/record.url?scp=85077951540&partnerID=8YFLogxK

U2 - 10.1016/j.optcom.2019.125184

DO - 10.1016/j.optcom.2019.125184

M3 - Article

AN - SCOPUS:85077951540

VL - 462

JO - Optics Communications

JF - Optics Communications

SN - 0030-4018

M1 - 125184

ER -