CIRCULAR DICHROIC THERMAL LENS MICROSCOPE

An objective of the present invention is to provide a circular dichroism thermal lens microscope apparatus capable of identifying and quantifying optically active samples in ultra-trace amounts, and which has a higher sensitivity than conventional apparatuses. The objective is achieved by a circular dichroism thermal lens microscope apparatus which beams excitation light and detection light into an optical microscope, where the detection light enters a thermal lens formed by irradiating a sample with the excitation light, and a substance in a sample is detected by determining the diffusion of the detection light by the thermal lens, and where the excitation light is modulated by a phase-modulation element, so as to identify or quantify an optical isomer.