Disordered Optics: Exploiting Multiple Light Scattering and Wavefront Shaping for Nonconventional Optical Elements

Abstract

Advances in diverse areas such as inspection, imaging, manufacturing, telecommunications, and information processing have been stimulated by novel optical devices. Conventional material ingredients for these devices are typically made of homogeneous refractive or diffractive materials and require sophisticated design and fabrication, which results in practical limitations related to their form and functional figures of merit. To overcome such limitations, recent developments in the application of disordered materials as novel optical elements have indicated great potential in enabling functionalities that go beyond their conventional counterparts, while the materials exhibit potential advantages with respect to reduced form factors. Combined with wavefront shaping, disordered materials enable dynamic transitions between multiple functionalities in a single active optical device. Recent progress in this field is summarized to gain insight into the physical principles behind disordered optics with regard to their advantages in various applications as well as their limitations compared to conventional optics.

Impact of fabrication errors and refractive index on multilevel diffractive lens performance

“…Various research groups have designed achromatic MDLs via careful parametric optimization of the lens surface topography in the visible 3,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] , NIR 26 , SWIR 27 , LWIR 28 , THz 29,30 and microwave 31 bands. In fact, we have recently shown the design of a single achromatic MDL with a focal length of 18 mm and aperture of ~ 1 mm, operating across a continuous spectrum of wavelengths from 450 nm to 15 μm 32,33 .…”

“…1(a); especially broadband MDLs, are fundamentally very different as they can be designed using the same principle of parametric optimization of the constituent elements; but operate across a continuous bandwidth at both low and high numerical apertures with high efficiency. Subwavelength structures have also recently been used to create planar lenses for achromatic focusing and other functionalities [4,[8][9][10]. These "metalenses" achieve abrupt phase shifts via resonance effects.…”

Speckle-Correlation Scattering Matrix Approaches for Imaging and Sensing through Turbidity

“…A known TM of an optical system such as a scattering media or a multi-mode fibre allows for direct control and the detection of waves [39,43,63]. However, the calibration of the TM is largely based on interferometry, which involves the modulation of incident waves and the measurement of the interference between a scattered and a reference wave [37,48].…”

“…Herein, we review a unique technique known as speckle-correlation scattering matrix (SSM) [36] that measures complex amplitudes of light by exploiting the 'randomness' of scattering media. The role of the scattering media is described by a transmission matrix (TM or T) [37][38][39][40][41] that expresses a relationship between the incident Einsicent and transmitted fields Etransmitted using a matrix equation as follows:…”

Enhancing sensitivity in absorption spectroscopy using a scattering cavity

“…Multiple light scattering has been exploited to increase the OPL and overcome the limitations of conventional optical elements 18 , including superlens 19 , temperature 20 , pressure sensing 21 , wavelength meters 22 , fiber-based spectrometers 23 , and non-resonant lasers 24 . The existing approaches employing the multiple scattering regime are represented by an integrating sphere 25 – 28 .…”