Quantitative phase imaging using a deep UV LED source

We propose a method for high resolution phase imaging of biological and non-biological samples using an incoherent deep ultraviolet (DUV) LED source. The diffraction pattern of the object wave is recorded at different axial planes and the phase is retrieved by propagation of the angular spectrum. To maintain enough light intensity, we avoided using a pinhole or spectral filter for increasing the coherence of the DUV LED source. This makes the setup very simple and cost effective. The short wavelength (285 nm) of the DUV light, tuned to the absorption peak of the biological samples, allows simultaneously high resolution and high contrast images. The experimental results are presented to verify this principle.