Optical Phase Retrieval Systems Using Color-Multiplexed Illumination

Patent Status

Brief Description

Light is a wave, having both an amplitude and phase. Our eyes and cameras, however, only see real values (i.e. intensity), so cannot measure phase directly. Phase is important, especially in biological imaging, where cells are typically transparent (i.e. invisible) but yet impose phase delays. When we can measure the phase delays, we get back important shape and density maps.

Researchers at the University of California, Berkeley have developed a new method for recovering both phase and amplitude of an arbitrary sample in an optical microscope from a single image, using patterned partially coherent illumination. The hardware requirements are compatible with most modern microscopes via a simple condenser insert, or by replacing the entire illumination pathway with a programmable LED array, providing flexibility, portability, and affordability, while eliminating many of the trade-offs required by other methods. This enables quantitative imaging of phase from a single image, using partially coherent illumination, and in a way that is flexible and amenable to a variety of existing microscopy systems.

Suggested uses

• Microscopy    

Advantages

• requires only a single image to recover both amplitude and phase
• achieves the same phase contrast images as conventional phase microscopies but with minimal hardware requirements
• cost effective
• twice the resolution compared to coherent phase retrieval techniques
• may be used in conjunction with a wide-variety of computational imaging techniques