Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
Journal Home About Issues in Progress Current Issue All Issues Feature Issues

Three-dimensional focusing through scattering media using conjugate adaptive optics with remote focusing (CAORF)

Xiaodong Tao, Tuwin Lam, Bingzhao Zhu, Qinggele Li, Marc R. Reinig, and Joel Kubby

Open Access Open Access

Abstract

The small correction volume for conventional wavefront shaping methods limits their application in biological imaging through scattering media. We demonstrate large volume wavefront shaping through a scattering layer with a single correction by conjugate adaptive optics and remote focusing (CAORF). The remote focusing module can maintain the conjugation between the adaptive optical (AO) element and the scattering layer during three-dimensional scanning. This new configuration provides a wider correction volume by better utilization of the memory effect in a fast three-dimensional laser scanning microscope. Our results show that the proposed system can provide 10 times wider axial field of view compared with a conventional conjugate AO system when 16,384 segments are used on a spatial light modulator. We also demonstrate three-dimensional fluorescence imaging, multi-spot patterning through a scattering layer and two-photon imaging through mouse skull tissue.

© 2017 Optical Society of America

Full Article  |  PDF Article
More Like This
Fourier conjugate adaptive optics for deep-tissue large field of view imaging

Lyubov V. Amitonova
Appl. Opt. 57(33) 9803-9808 (2018)

Bidirectional image transmission through physically thick scattering media using digital optical phase conjugation

Mu Qiao, Honglin Liu, and Shensheng Han
Opt. Express 26(25) 33066-33079 (2018)

Adaptive optics enables aberration-free single-objective remote focusing for two-photon fluorescence microscopy

Yuhan Yang, Wei Chen, Jiang Lan Fan, and Na Ji
Biomed. Opt. Express 12(1) 354-366 (2021)

View More...

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (13)
Fig. 1
Fig. 1 A schematic diagram of AO laser scanning systems. (a) Pupil AO. The SLM is conjugated with the pupil plane. The projected wavefront at the scattering layer moves with the scanning beam. The effective number of segments decreases with the axial shift. (b) Conjugate AO (CAO). The SLM is located at the plane that is conjugate to the scattering layer. The projected phase changes with the axial shift. (c) CAO and remote focusing (CAORF). The projected phase on the scattering layer does not change during three-dimensional scanning.

Download Full Size | PDF

Fig. 2
Fig. 2 Schematic of the experimental setup. A lens (L1) collimates the laser beam from a 488nm solid-state laser. A lens (L2) installed on a three-axis translation stage works as a remote focusing (RF) and two-dimensional (2D) scanning module. The conjugate AO module consists of a spatial light modulator (SLM) and a folding mirror (M1), which are installed on a single-axis translation stage. The lens (L3) and an objective lens (O1) image the SLM plane onto the scattering lay. The light is collected by another objective lens (O2) and focused by a lens (L4) on a CCD camera.

Download Full Size | PDF

Fig. 3
Fig. 3 Wavefront shaping by measuring the transmission matrix. (a) The whole aperture is randomly divided into two groups of segments. (b) The optimal phase of the first group after the transmission matrix measurement. (c) After the optimal phase for the second group of segments is achieved, the combined phase mask is displayed on the SLM. The image before correction, after the first correction and after the second correction are shown in (d), (e) and (f) respectively. The scale bar is 5 µm.

Download Full Size | PDF

Fig. 4
Fig. 4 Field of view analysis for 3d scanning for CAORF (a) and CAO without RF (b). The normalized intensity of the focal spot scanning along the X-Z plane for these two configurations are shown in (c) and (d), respectively. (e) The normalized intensity of the focal spot along the center of the field versus the axial shift. The red and blue dashed curves show measurement results for CAORF and CAO, respectively. The simulation of CAORF (a) is indicated by the blue curve.

Download Full Size | PDF

Fig. 5
Fig. 5 Effect of the axial shift on the normalized intensity of the focal spot for different numbers of segments with CAORF and CAO. The measurements with CAORF and CAO are indicated by triangles and squares. The solid curves shows the simulation results in each case. The results for 1024, 4096 and 16,384 segments are indicated by blue, red and green, respectively.

Download Full Size | PDF

Fig. 6
Fig. 6 (a) Images of the focal spot at different focal planes for CAO and CAORF. (b) The full-width-half-maximum (FWHM) of the focal spot at different focal distances. The measurements for CAO and CAORF are indicated by blue and red lines. The theoretical resolution is indicated by the green line. The scale bar is 2µm.

Download Full Size | PDF

Fig. 7
Fig. 7 Axial scanning of 3d patterns with RF. (a) Two patterns at two focal planes (Z = 0 µm and 120 µm) are generated simultaneously by combing two phase masks. The remote focusing module shifts the focal plane with a range of 120 µm. (b) The corresponding images at different focal planes are captured by the CCD camera. (c) The average intensity enhancement of the focal spots at different depth. The scale bar is 10 µm.

Download Full Size | PDF

Fig. 8
Fig. 8 Comparison of 3d fluorescent imaging with CAO and CAORF. (a) The sample is placed 2mm behind the scattering layer. The beam is translated in the X-Y plane by the 2d scanning module. The emission light is collected by the detector, which gives the intensity information for each scan position to generate a 2d image. (b) The image without wavefront shaping. (c) The images at depths of 0 µm, 50 µm, 100 µm and 150 µm without RF. The depth is adjusted by moving the scattering layer. (d) The images at depths of 100 µm, 200 µm, 300 µm and 500 µm with CAORF. The depth is adjusted by the remote focusing module. (e) and (f) Enlarged views of the areas highlighted in (c) and (d), respectively. (g) The transmission microscope image of the same area. The scale bar is 50µm.

Download Full Size | PDF

Fig. 9
Fig. 9 Two-photon imaging of fluorescent microspheres through a mouse skull. (a) A schematic diagram of the imaging configuration. A piece of mouse skull is mounted on a 170 µm thick coverslip. Agarose gel with a thickness of 3mm is sandwiched between two coverslips. The initial correction is applied on the microspheres just below the first coverslip. (b) The phase for compensation of the scattering. (c) The images of microspheres at the top of the agarose gel (depth = 0 µm) with and without correction. The green boxes indicate the enlarged view. (d) Images at depths of 14 µm, 36 µm and 42 µm with the CAORF system and the conventional CAO system. (e) The intensity profile along the line indicated in (d). The scale bar is 5 µm.

Download Full Size | PDF

Fig. 10
Fig. 10 Effective segments change due to the conjugation error from an axial shift. (a) & (b) show the effective segments in one and two dimensional space, respectively.

Download Full Size | PDF

Fig. 11
Fig. 11 Calculation of the correlation function based on the memory effect. (a) The original configuration using an angular FOV. (b) The general configuration for three-dimensional scanning.

Download Full Size | PDF

Fig. 12
Fig. 12 (a) Normalized intensity versus lateral shift and (b) Normalized intensity along the X and Z plane.

Download Full Size | PDF

Fig. 13
Fig. 13 System setup diagram. (a) The setup used for system evaluation. A lens (L1) collimates the laser beam from a 488nm solid-state laser. A lens (L2) installed on a three-axis translation stage works as a remote focusing (RF) and two-dimensional (2D) scanning module. The conjugate AO module consists of a spatial light modulator (SLM) and a folding mirror (M1), which are installed on a single-axis translation stage. The lens (L3) and an objective lens (O1) image the SLM plane onto the scattering layer. The light is collected by another objective lens (O2) and focused by a lens (L4) onto a CCD camera. (b) The additional modification for two-photon imaging through a mouse skull sample. Two galvanometers are used for fast scanning. L5 and L6 are relay lenses between the two scanners. Lens L7 and L8 direct the beam to the remote focusing lens (L2). A photomultiplier (PMT) and a dichroic mirror (D1) are added to the system to collect the emission light from the sample.

Download Full Size | PDF

Equations (12)

Equations on this page are rendered with MathJax. Learn more.

X FOV ~2 σ SLM ,
η Δz ~ ( ∑ n α n,Δz N ) 2 ,
Z FOV ~2Z X FOV /D,
t obs i = ( I i 0 − I i π ) /4 + ( I i 3π/2 − I i π/2 ) /4 .
E in = T obs ' / | T obs ' | ,
E out =T E in = ∑ n t n E in n ,
E ideal =A ∑ n | t n | .
E Δz =A ∑ n α n,Δz | t n | ,
η Δz = 〈 E Δz 2 〉 〈 E ideal 2 〉 ~ ( ∑ n α n,Δz N ) 2 .
C θ (θ,L)= kθL sinh(kθL) ,
ϕ= k ρ 2 Δ z 2Z(Z− Δ z ) + k(x Δ x +y Δ y ) Z
C x,y,z ( Δ x , Δ y , Δ z )= ∬ C θ ( dϕ dρ ,L)dxdy ∬ C θ (0,L)dxdy
Select as filters
Select Topics Cancel
Top
       
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.
Privacy | Terms of Use