Absorption of Pulsed Terahertz and Optical Radiation in Earthworm Tissue and Its Heating Effect

Abstract The transmission of THz, near-infrared (1030 nm), and green (515 nm) pulses through Eisenia andrei body wall is studied, which consists epithelial layer circular longitudinal muscles. Samples with the full-body cross-section were also investigated. transmitted power for followed Beer-Lambert law exponential attenuation all thicknesses tissue structures. Different center absorption coefficients found in case infrared pulses. In THz range, coefficient steadily increases from about 80 cm –1 at 0.2 to 273 2.5 THz. Numerical estimation indicates that 5-?J energy 1-kHz repetition rate (5-mW average power) cause only a small temperature increase 0.4 K, suggesting heating has minor contribution biological effectiveness.