Instantaneous Non-Diffracting Light-Sheet Generation Using Controlled Spatial Coherence

Abstract

University of Central Florida researchers have developed an easily implementable method for enhanced high-resolution, light-sheet fluorescence imaging without using a beam scanning module or a phase modulation system.  The UCF single-shot, non-diffracting light-sheet generation technique provides a much larger field-of-view and higher signal-to-background ratio than current techniques requiring such equipment. In experimental results, the method generated a light sheet with a propagation distance approximately seven times longer than a typical Gaussian light sheet with a similar beam waist. Applications for the technology include single-molecule fluorescence imaging, high-throughput transcriptomics, super-resolution fluorescence imaging and tissue imaging.

Technical Details

The UCF invention employs controlled spatial coherence to generate static, non-diffracting optical light-sheets without using a beam scanning module or a spatial light modulator (SLM). For example, a one-dimensional (1D) coherent beam can be generated by increasing the spatial coherence of a light-emitting diode (LED) through an annular mask placed at the back focal plane (BFP).

As shown in the example schematic, incoherent light from an LED is collected and collimated by a condenser lens (F1) and focused by a cylindrical lens (CL). The beam passes through a narrow slit placed at the BFP of the cylindrical lens to control the spatial coherence. Then the slit is conjugated to an image plane using a relay system comprising a lens (F2) and an objective lens. An annular ring with outer and inner diameters of 2 mm and 1.75 mm, respectively, is inserted at the BFP of the objective. The beam emanating from the slit is a 1D coherent beam. It virtually produces numerous focused lines at the different positions of the BFP while illuminating the entirety of the annular mask. In the example, the beam propagation length is 6.75 mm, and its thickness is approximately 14.5 µm, comparable to a laterally scanned Bessel beam. In another example, a 1D coherent beam can also be created by decreasing the spatial coherence of a laser, making it unnecessary to scan non-diffracting beams to generate light sheets.

Partnering Opportunity

The research team is looking for partners to develop the technology further for commercialization.

Stage of Development

Prototype available.

Benefit

Market Application

Publications

Instantaneous non-diffracting light-sheet generation by controlling spatial coherence, Optics Communications, Volume 474, 2020, https://doi.org/10.1016/j.optcom.2020.126154.