Rotational scanning and multiple-spot focusing through a multimode fiber based on digital optical phase conjugation

Abstract

We demonstrate, for the first time, the rotational memory effect of a multimode fiber (MMF) based on digital optical phase conjugation (DOPC) to achieve multiple-spot focusing. An implementation interferometer is used to address the challenging alignments in DOPC. By rotating the acquired phase conjugate pattern, rotational scanning through a MMF could be achieved by recording a single off-axis hologram. The generation of two focal spots through a MMF is also demonstrated by combining the rotational memory effect with the superposition principle. The results may be useful for ultrafast scanning imaging and optical manipulation of multiple objects through a MMF.

In pursuit of high‐fidelity waveguide imaging restoration using deep learning algorithms: A review

“…To address imaging distortion, computational imaging (CI) techniques have been developed over the past few decades. Specifically, these methods include phase conjugation [19,20], wavefront shaping [21] and the computation of the waveguide transmission matrix [22][23][24]. They aim to identify and correct deteriorated images at the distal end of optical waveguides, thus facilitating image recovery.…”

A scanning-free wide-field single-fiber endoscopic image retrieval method based on optical transmission matrix

“…In fact, many methods have been proposed recently as for the endoscopic imaging applications using MMF [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. These methods can be classified into two main types.…”

“…One is the spot-scanning method (so-called the localized-sampling method), the other is the wide-field imaging method. The spot-scanning method, which includes the wavefront shaping method [4][5][6][7][8][9][10][11], the digital phase conjugation method [12][13][14][15][16] and the optical transmission matrix (TM) method [18,19], has been verified to be capable of controlling the light waves…”

Lensless multimode fiber imaging based on wavefront shaping

“…Therefore, the key of a single MMFendoscopic imaging lies in overcoming the mode dispersion. To make full use of the advantage of parallel transmission of information in a MMF and overcome spatial distortions, various wavefront shaping methods, including transmission matrix (TM) measurements, [16][17][18] digital phase conjugation [19][20][21] and iterative optimization algorithms, 22) are being actively developed for compensating the effects of mode dispersion. Unfortunately, above-mentioned techniques suffer from several limitations.…”