High-resolution Brillouin spectroscopy with angular dispersion-type Fabry-Perot interferometer and its application to...

Area of Science:

• Physics
• Materials Science

Background:

• Multichannel Brillouin spectroscopy using angular dispersion-type Fabry-Perot interferometers (ADFPI) offers rapid measurements.
• Existing ADFPI methods lack sufficient resolution and contrast for detailed single crystal studies.

Purpose of the Study:

• To enhance the resolution and contrast of multichannel Brillouin spectroscopy for single crystal analysis.
• To investigate the elastic properties of quartz crystals, particularly during the alpha-beta phase transition.

Main Methods:

• Utilized a highly sensitive multichannel detector with a solid etalon of high reflectivity (99.5%).
• Achieved high spectral resolution and contrast, with finesse reaching up to 100 (10 mm aperture) and 140 (2 mm aperture).

Main Results:

• Demonstrated significantly improved resolution and contrast in spectral measurements.
• Successfully investigated weak attenuation phenomena in quartz crystals.
• Clearly observed the elastic anomaly associated with the alpha-beta transition in quartz, analyzing sound velocity and attenuation.

Conclusions:

• The enhanced ADFPI technique is suitable for detailed studies of single crystals, including weak attenuation.
• The method accurately characterizes elastic anomalies and phase transitions, as evidenced by quartz crystal measurements.
• Determined the critical parameter K=0.76 from the elastic constant c(11) of quartz.