Perspective: Wavefront shaping techniques for controlling multiple light scattering in biological tissues: Toward in vivo applications

Abstract

Multiple light scattering has been regarded as a barrier in imaging through complex media such as biological tissues. Owing to recent advances in wavefront shaping techniques, optical imaging through intact biological tissues without invasive procedures can now be used for direct experimental studies, presenting promising application opportunities in in vivo imaging and diagnosis. Although most of the recent proof of principle breakthroughs have been achieved in the laboratory setting with specialties in physics and engineering, we anticipate that these technologies can be translated to biological laboratories and clinical settings, which will revolutionize how we diagnose and treat a disease. To provide insight into the physical principle that enables the control of multiple light scattering in biological tissues and how recently developed techniques can improve bioimaging through thick tissues, we summarize recent progress on wavefront shaping techniques for controlling multiple light scattering in biological tissues.

A comparative study of optimization algorithms for wavefront shaping

“…Another novel method is Binary phase Easy 50 23 46 40 TM Medium 100 37 23 53 PSO Medium 40 16 38 31 GA Di±cult 45 20 40 35 SA Di±cult 85 30 69 61 wavefront shaping which achieves a higher enhancement than binary amplitude wavefront shaping, and it also achieves a higher speed than full phase wavefront shaping, which is crucial for in vivo applications where the sample persistence time is very short. 11,46 With the advancement of the development of the SLM, the wavefront shaping will be more spread out and can be used in optical imaging techniques such as optical coherence topography for deep structural imaging. 44,47,48…”

“…Wavefront shaping has been used in di®erent high-resolution imaging modalities such as optical coherence tomography (OCT),°uorescence microscopy, two-photon microscopy (TPM), and photoacoustic microscopy (PAM) to improve their resolution or penetration depth. 1,2 Wavefront shaping using computer-controlled spatial light modulators (SLMs) has been widely used in these modalities 1,[3][4][5][6][7][8][9][10][11] and hence, choosing an appropriate optimization algorithm for a particular modality or application is of prime importance.…”

Holotomography: refractive index as an intrinsic imaging contrast for 3-D label-free live cell imaging

“…Yet, deep tissue imaging toward applications in dermatology or gastroenterology is technically challenging due to multiple light scattering (Yu et al 2015). There are several attempts to overcome multiple light scattering including optical coherence tomography using wavefront shaping Park et al 2018c;Yu et al 2014;Yu et al 2016) or accumulating single scattering light in deep tissue imaging .…”

Artificial intelligence-assisted light control and computational imaging through scattering media

“…Optical wavefront shaping (WFS) 1,2,4-6 is developed to compensate for the scattering-induced phase distortions, where a spatial light modulator (SLM) with discrete elements is typically employed to resolve the continuous wavefront. 7 By controlling millions of modes to shape the incident light, not only di®raction-limited optical focusing 2,4,8,9 but also arbitrary intensity pro¯le (e.g., images) transmission [10][11][12] can be achieved through or within highly scattering media. Depending on how we optimize the wavefront displayed on the SLM, the current implementations can be categorized into two groups: time-reversed WFS and iterative WFS.…”