Role of Phase Information Propagation in the Realisation of Super-Resolution Based on Speckle Interferometry

Abstract

Super-resolution technology is important not only in bio-related fields but also in nanotechnology, particularly in the semiconductor industry, where fine patterning is required and super-resolution is essential. However, observing microstructures beyond the diffraction limit proposed by Abbe and Rayleigh is considered impossible because of diffraction in traditional optical microscopy observation techniques. However, in recent years, it has been possible to observe microstructures beyond the Rayleigh criterion by analysing the phase distribution of light. This study investigated the physical reasons why phase analysis makes this new analysis technique possible using simulations. The results confirmed that the phase component of the zero-order diffracted light reflected from the microstructure and able to pass through the lens system contained phase information related to the shape of the measured object. Analysis of this information demonstrates the possibility of realising super-resolution based on speckle interferometry.

Improved Optics for Super-Resolution Time-Lapse Observations of Biological Phenomenon Using Speckle Interferometry

“…Consequently, the experimental results demonstrated that detecting the phase distribution according to the shape of the object was possible, even outside of the focal plane. Additionally, the validity of the simulation results presented in a previous paper [25] was experimentally confirmed. In the course of this verification process, it was also demonstrated that the spatial resolution of the present optical system could be easily improved by applying to it the traditional speckle-handling methods [26], commonly used in speckle interferometry.…”

“…Figure 6b,d show that a sinusoidal shape could be observed in almost the same manner, although the amplitudes were slightly different. These results show that the shape information of the object was preserved in the phase distribution of the reflected light from the object, not only considering the simulation results shown in [25], but also the experimental results.…”

“…Such an optical observation system has the potential to contribute to the future development of biological research. Furthermore, using this new optical system and simulation results from a previous study [25], this study experimentally clarified that the phase distribution of the reflected light from the measured object would propagate accurately with the shape information of the observation object. Analysis of this phase distribution at a high resolution confirmed that super-resolution could be achieved using only the light that passed through the lens aperture without any higher-order diffracted light.…”

“…The simulation results in a previous study [25] reported that the phase information contained within the light reflected from the surface of the object depended on the shape of the object. By proving that the surface shape information of an object would be preserved in the phase component of the light reflected from the object, this study experimentally confirmed that the proposed method enables the observation of microstructures beyond the diffraction limit.…”

“…Considering the need for tools to observe cellular tissues beyond the diffraction limit, a new observation method using speckle interferometry [21][22][23] was reported, which could provide super-resolution two-dimensional images [24]. This new technology [25] achieves super-resolution by analysing the phase distribution contained in the reflected light from the observed object. However, in the optical systems adopted in super-resolution technologies based on speckle interferometry developed thus far, the optical axis is set parallel to the horizontal plane of the vibration-isolation table; this setup is identical to that of general interferometry [24].…”