Modulation of Point Spread Function for Super-Resolution Imaging

A four-dimensional (4D) super-resolution imaging method (called PSF modulation method) was developed via modulation of an arbitrary point-spread-function (PSF) of an imaging system. The highest image resolution achievable will only be limited by the noises in the images. Theory, computer simulations, and experiments were presented. 

A pulse-echo image of a super-resolution (0.65 mm versus a two-way diffraction-limited resolution of 2.65 mm) and 31-dB signal-to-noise ratio (SNR) was obtained with an ultrasound experiment using a 0.5-mm diameter modulator and 1.483-mm wavelength. Another ultrasound experiment shows that a wave source was imaged at a super-resolution (0.5 mm versus a one-way diffraction limited resolution of 3.63 mm) at about 30-dB SNR, using the same modulator size and wavelength. 

In addition, a PSF-weighted super-resolution imaging method based on the PSF modulation method was developed. This method is easier to implement but may have some limitations. With a proper choice of a modulator and imaging system, nanoscale imaging is possible using the methods developed.