RF and Microwave Photonic techniques in biomedical applications

This invited paper addresses various "microwave photonics" techniques developed for biomedical applications. The first application is using RF photonics technique for calibration of ultrasound transducers operating at high-frequencies without spatial field averaging compromise. In particular a broadband fiber-optic based hydrophone probe is reported for measurements of acoustic fields at the frequencies up to 100 MHz. In another application of microwave photonics, tissue spectroscopy is performed using multi-wavelength absorption and scattering in near infrared. A high speed and high power laser driver is designed with a flat frequency response using RC speed up circuits in high power lasers. Phantom experiments are performed to extract optical parameters. Multi-frequency data fitting algorithm is performed to extract optical parameters of the phantom model simulating a breast tissue. The optical parameters (mua, mus') are extracted with a very good accuracy. These low cost techniques are replacement for other expensive sub-centimeter spatial resolution medical imaging methods.