Abstract

A new real-time laser differential confocal microscopy (RLDCM) without sample reflectivity difference effects is proposed for imaging height topography of sample surface, which divides the confocal microscopy imaging light path into two confocal microscopy imaging paths before and after focus with the equal axial detector offset oriented in opposite direction. By dividing the difference of the two signals simultaneously detected from these two confocal imaging paths by the higher signal between these two signals, RLDCM separates the signal that comes from reflectivity heterogeneity from the topographic signal in real time for the first time. RLDCM significantly reduces the height topography imaging time by single-layer scanning for the sample surface with reflectivity heterogeneity, and it achieves high axial resolution and lateral resolution similar to CM by optimizing the axial detector offset. Theoretical analysis and experimental results demonstrate that RLDCM realizes the real-time surface imaging for line structures featuring Silicon Dioxide steps on a Silicon base and achieves 2-nm axial depth resolution without reducing lateral resolution.

© 2014 Optical Society of America

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References

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2012

2010

2007

2006

K. Taehoon, K. Taejoong, L. Seung Woo, G. Dae-Gab, and S. Jungwoo, “Optimum conditions for high-quality 3D reconstruction in confocal scanning microscopy,” Proc. SPIE 6090, 181–187 (2006).

W. Zhao, L. Qiu, S. Chen, and Z. Feng, “Image Restoration Phase-Filtering Lateral Superresolution Confocal Microscopy,” Chin. Phys. Lett. 23(4), 856–859 (2006).
[CrossRef]

2004

2003

2002

2000

1999

1997

C. Lee and J. Wang, “Noninterferometric differential confocal microscopywith 2-nm depth resolution,” Opt. Commun. 135(4-6), 233–237 (1997).
[CrossRef]

1994

M. Visscher and K. G. Struik, “Optical profilometry and its application to mechanically inaccessible surfaces Part I: Principles of focus error detection,” Precis. Eng. 16(3), 192–198 (1994).
[CrossRef]

M. Gu and C. J. R. Sheppard, “Effects of defocus and primary spherical aberration on images of a straight edge in confocal microscopy,” Appl. Opt. 33(4), 625–630 (1994).
[CrossRef] [PubMed]

1993

1991

Aguilar, J. F.

Arrasmith, C. L.

Caballero, M.

Chen, S.

W. Zhao, L. Qiu, S. Chen, and Z. Feng, “Image Restoration Phase-Filtering Lateral Superresolution Confocal Microscopy,” Chin. Phys. Lett. 23(4), 856–859 (2006).
[CrossRef]

Chen, T.

Dae-Gab, G.

K. Taehoon, K. Taejoong, L. Seung Woo, G. Dae-Gab, and S. Jungwoo, “Optimum conditions for high-quality 3D reconstruction in confocal scanning microscopy,” Proc. SPIE 6090, 181–187 (2006).

Dickensheets, D. L.

Feng, Z.

W. Zhao, L. Qiu, S. Chen, and Z. Feng, “Image Restoration Phase-Filtering Lateral Superresolution Confocal Microscopy,” Chin. Phys. Lett. 23(4), 856–859 (2006).
[CrossRef]

Gu, M.

Herrmann, K.

Hewlett, S. J.

Ibáñez-López, C.

Jungwoo, S.

K. Taehoon, K. Taejoong, L. Seung Woo, G. Dae-Gab, and S. Jungwoo, “Optimum conditions for high-quality 3D reconstruction in confocal scanning microscopy,” Proc. SPIE 6090, 181–187 (2006).

Kimura, S.

Lee, C.

C. Lee and J. Wang, “Noninterferometric differential confocal microscopywith 2-nm depth resolution,” Opt. Commun. 135(4-6), 233–237 (1997).
[CrossRef]

Lee, C. H.

Lera, M.

Li, Z.

Liu, C.

Mahadevan-Jansen, A.

Martinez-Corral, M.

Pohlenz, F.

Qiu, L.

Qu, J.

Ruprecht, A. K.

Saavedra, G.

Seung Woo, L.

K. Taehoon, K. Taejoong, L. Seung Woo, G. Dae-Gab, and S. Jungwoo, “Optimum conditions for high-quality 3D reconstruction in confocal scanning microscopy,” Proc. SPIE 6090, 181–187 (2006).

Sheppard, C. J. R.

Struik, K. G.

M. Visscher and K. G. Struik, “Optical profilometry and its application to mechanically inaccessible surfaces Part I: Principles of focus error detection,” Precis. Eng. 16(3), 192–198 (1994).
[CrossRef]

Taehoon, K.

K. Taehoon, K. Taejoong, L. Seung Woo, G. Dae-Gab, and S. Jungwoo, “Optimum conditions for high-quality 3D reconstruction in confocal scanning microscopy,” Proc. SPIE 6090, 181–187 (2006).

Taejoong, K.

K. Taehoon, K. Taejoong, L. Seung Woo, G. Dae-Gab, and S. Jungwoo, “Optimum conditions for high-quality 3D reconstruction in confocal scanning microscopy,” Proc. SPIE 6090, 181–187 (2006).

Tan, J.

Tiziani, H. J.

Tsai, C. W.

Visscher, M.

M. Visscher and K. G. Struik, “Optical profilometry and its application to mechanically inaccessible surfaces Part I: Principles of focus error detection,” Precis. Eng. 16(3), 192–198 (1994).
[CrossRef]

Wang, J.

C. W. Tsai, C. H. Lee, and J. Wang, “Deconvolution of local surface response from topography in nanometer profilometry with a dual-scan method,” Opt. Lett. 24(23), 1732–1734 (1999).
[CrossRef] [PubMed]

C. Lee and J. Wang, “Noninterferometric differential confocal microscopywith 2-nm depth resolution,” Opt. Commun. 135(4-6), 233–237 (1997).
[CrossRef]

Wiesendanger, T. F.

Wilson, T.

Yu, H.

Zhao, W.

Appl. Opt.

Chin. Opt. Lett.

Chin. Phys. Lett.

W. Zhao, L. Qiu, S. Chen, and Z. Feng, “Image Restoration Phase-Filtering Lateral Superresolution Confocal Microscopy,” Chin. Phys. Lett. 23(4), 856–859 (2006).
[CrossRef]

Opt. Commun.

C. Lee and J. Wang, “Noninterferometric differential confocal microscopywith 2-nm depth resolution,” Opt. Commun. 135(4-6), 233–237 (1997).
[CrossRef]

Opt. Express

Opt. Lett.

Precis. Eng.

M. Visscher and K. G. Struik, “Optical profilometry and its application to mechanically inaccessible surfaces Part I: Principles of focus error detection,” Precis. Eng. 16(3), 192–198 (1994).
[CrossRef]

Proc. SPIE

K. Taehoon, K. Taejoong, L. Seung Woo, G. Dae-Gab, and S. Jungwoo, “Optimum conditions for high-quality 3D reconstruction in confocal scanning microscopy,” Proc. SPIE 6090, 181–187 (2006).

Other

M. Gu, Three-Dimensional Imaging in Confocal Microscopes (World Scientific, 1996), chap.3.

T. Wilson, Confocal microscopy (Academic, 1990), chap.1.

G. S. Kino and T. R. Corle, Confocal Scanning Optical Microscopy and Related Imaging Systems (Academic, 1996).

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Figures (17)

Fig. 1
Fig. 1

Schematic diagram of RLDCM.

Fig. 2
Fig. 2

RLDCM axial response curvess at various ud.

Fig. 3
Fig. 3

R-squared and ΔE/r curves with different ud.

Fig. 4
Fig. 4

RLDCM’s axial response curve with ud = 1.27.

Fig. 5
Fig. 5

Simulation RLDCM imaging curves of height-step 1 with ut = 1, ub = −1, Rt = 1 and Rb = 1. (a) IA and IB curves. (b) IC, Imax and Id curves. (c) Height curve.

Fig. 6
Fig. 6

Simulation RLDCM imaging curves of height-step 2 with ut = 1, ub = −1, Rt = 1 and Rb = 21/2. (a) IA and IB curves. (b) IC, Imax and Id curves. (c) Height curves.

Fig. 7
Fig. 7

Simulation RLDCM imaging curves of height-step 3 with ut = 1.2, ub = −1, Rt = 1 and Rb = 1. (a) IA and IB curves. (b) IC, Imax and Id curves. (c) Height curves.

Fig. 8
Fig. 8

Simulation RLDCM imaging curves of height-step 4 with ut = 1.2, ub = −1, Rt = 1and Rb = 21/2. (a) IA and IB curves. (b) IC, Imax and Id curves. (c) Height curves.

Fig. 9
Fig. 9

Simulation of the imaging curves of the height-step using CM, RLDCM, BADCM and DCM.

Fig. 10
Fig. 10

Defocusing IPSF curves |hA(v,u + 1.27)|2 of confocal imaging path A. (a) Raw curves, and (b) Normalized curves.

Fig. 11
Fig. 11

The profile image curves with different ut.

Fig. 12
Fig. 12

Real-time laser differential confocal microscope.

Fig. 13
Fig. 13

Measured axial response curve and fitted height sensing curve. (a) Measured axial response curve; and (b) Fitted height sensing curve.

Fig. 14
Fig. 14

The line structures of HS–500MG. (a) the cross-section view of the structures.(b) Full-focus intensity image of the structures obtained by CM. (d) Height image of the structures obtained by CM. (d) Height measurements of the structures scanned by AFM.

Fig. 15
Fig. 15

The measurements of the line structures scanned by RLDCM. (a) IA image. (b) IB image. (c) Imax image. (d) Height image zm. (e) IA and IB intensity profile at the position indicated by the dashed lines in (a) and (c). (f) Imax intensity profile and zm height profile at the position indicated by the dashed lines in (c) and (d). (g) Histogram for zm.

Fig. 16
Fig. 16

3-D surface profile of HS-500MG obtained by RLDCM.

Fig. 17
Fig. 17

Filtered and estimation curves of true height profile at the position indicated by the dashed line in Fig. 15(d).

Tables (3)

Tables Icon

Table 1 Comparison of Height-Steps Imaging

Tables Icon

Table 2 Comparison of ERDs and ESs

Tables Icon

Table 3 Measurement Comparison between RLDCM and AFM

Equations (12)

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I A ( v xs , v ys ,u)= | [ R( v xs , v ys ) h 1 ( v xs , v ys ,u) h A2 ( v xs , v ys ,u,+ u d ) ] 3 o( v xs , v ys ,u) | 2 , I B ( v xs , v ys ,u)= | [ R( v xs , v ys ) h 1 ( v xs , v ys ,u) h B2 ( v xs , v ys ,u, u d ) ] 3 o( v xs , v ys ,u) | 2 .
I d ( v xs , v ys ,u)= I B ( v xs , v ys ,u) I A ( v xs , v ys ,u), I max ( v xs , v ys ,u)=max[ I A ( v xs , v ys ,u), I B ( v xs , v ys ,u)] ={ I B ( v xs , v ys ,u), I B ( v xs , v ys ,u) I A ( v xs , v ys ,u) I A ( v xs , v ys ,u), I B ( v xs , v ys ,u)< I A ( v xs , v ys ,u) .
I( v xs , v ys ,u)= I d ( v xs , v ys ,u) I max ( v xs , v ys ,u) ={ 1 I A ( v xs , v ys ,u) I B ( v xs , v ys ,u) , I B ( v xs , v ys ,u) I A ( v xs , v ys ,u) I B ( v xs , v ys ,u) I A ( v xs , v ys ,u) 1, I B ( v xs , v ys ,u)< I A ( v xs , v ys ,u)
I( v xs , v ys ,u)=1 | [ R h 1 ( v xs , v ys ,u) h A2 ( v xs , v ys ,u,+ u d ) ] 3 o( v xs , v ys ,u) | 2 | [ R h 1 ( v xs , v ys ,u) h B2 ( v xs , v ys ,u, u d ) ] 3 o( v xs , v ys ,u) | 2 =1 | [ h 1 ( v xs , v ys ,u) h A2 ( v xs , v ys ,u,+ u d ) ] 3 o( v xs , v ys ,u) [ h 1 ( v xs , v ys ,u) h B2 ( v xs , v ys ,u, u d ) ] 3 o( v xs , v ys ,u) | 2 .
I(u, u d )= { sin[(2u+ u d )/4] (2u+ u d )/4 } 2 =sin c 2 ( u/2+ u d /4 )
I A (u, u d )= R 2 sin c 2 ( u/2+ u d /4 ), I B (u, u d )= R 2 sin c 2 ( u/2 u d /4 )
I(u, u d )={ 1 sin c 2 ( u/2+ u d /4 ) / sin c 2 ( u/2 u d /4 ) , I B (u, u d ) I A (u, u d ) sin c 2 ( u/2 u d /4 ) / sin c 2 ( u/2+ u d /4 ) 1, I B (u, u d )< I A (u, u d ) .
u( v xs , v ys )=f[ I( v xs , v ys ) ].
u( v x )={ u t , v x 0 u b , v x <0 ,R( v x )={ R t , v x 0 R b , v x <0
| h A (v,u,+1.27) | 2 = | 0 1 P(ρ)exp( iu ρ 2 2 ) J 0 (vρ) ρdρ 0 1 P(ρ)exp[ i(u+1.27) ρ 2 2 ] J 0 (vρ)ρ dρ | 2 ,
| I I |=| { [ (1+η) I B + n B ] (1+η) I A + n A 1 }[ I B I A 1 ] |=| ΔnI n A I A +η I A + n A || I n A I A |.
h h m = 0 α 0 n 2 sin 2 θ cosθ sinθdθ 0 α 0 sinθdθ ,

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