Abstract

Improved differential confocal microscopy is proposed to improve axial resolution and to enhance disturbance resistibility of confocal microscopy. The subtraction and sum values of the two defocusing detected signals are divided as the response function. Both ultrahigh signal-to-noise ratio (SNR) and wide range can be selectively obtained by controlling the defocusing amount of the two differential detectors more tightly with the reflectance disturbance resistibility. Since the detecting sensitivity of the proposed confocal microscopy is unrelated to the energy loss of the reflected beam, the multiplicative mode disturbance can be used to measure microstructures made of hybrid materials and overcome the power drift of a laser source during long scanning. In the case of ultrahigh SNR, the axial resolution reaches 1nm when NA=0.75 and λ=632.8nm.

© 2009 Optical Society of America

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References

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2008

2007

2004

2002

J. Tan and F. Wang, “Theoretical analysis and property study of optical focus detection based on differential confocal microscopy,” Meas. Sci. Technol. 13, 1289-1293 (2002).
[CrossRef]

1998

B. V. R. Tata and B. Raj, “Confocal laser scanning microscopy: Applications in material science and technology,” Bull. Mater. Sci. 21, 263-278 (1998).
[CrossRef]

1996

1988

Carlini, A. R.

Cho, K.

Davis, B. J.

DiMarzio, C. A.

Fang, Z. P.

Goldberg, B.

Juškaitis, R.

Karl, W. C.

Kim, B. S.

Köklü, F. H.

Kozubek, M.

Kwon, K. H.

Li, S. G.

Lin, D.

Liu, Z.

Neil, M. A. A.

Qiu, L. R.

Quesnel, J. I.

Raj, B.

B. V. R. Tata and B. Raj, “Confocal laser scanning microscopy: Applications in material science and technology,” Bull. Mater. Sci. 21, 263-278 (1998).
[CrossRef]

Reading, I.

Sheppard, C. J. R.

C. J. R. Sheppard, “Fundamentals of superresolution,” Micron 38, 165-169 (2007).
[CrossRef]

Swan, A. K.

Tan, J.

J. Tan and F. Wang, “Theoretical analysis and property study of optical focus detection based on differential confocal microscopy,” Meas. Sci. Technol. 13, 1289-1293 (2002).
[CrossRef]

Tan, J. B.

Tata, B. V. R.

B. V. R. Tata and B. Raj, “Confocal laser scanning microscopy: Applications in material science and technology,” Bull. Mater. Sci. 21, 263-278 (1998).
[CrossRef]

Ünlü, M.

Vamivakas, A. N.

Wang, F.

J. Tan and F. Wang, “Theoretical analysis and property study of optical focus detection based on differential confocal microscopy,” Meas. Sci. Technol. 13, 1289-1293 (2002).
[CrossRef]

Warger, W. C.

Wilson, T.

Xu, Z. G.

Xu, , Y.

Yan, J.

Yin, C.

Yoon, S. F.

Zhang, R.

Zhao, J.

Zhao, W. Q.

Appl. Opt.

Bull. Mater. Sci.

B. V. R. Tata and B. Raj, “Confocal laser scanning microscopy: Applications in material science and technology,” Bull. Mater. Sci. 21, 263-278 (1998).
[CrossRef]

Meas. Sci. Technol.

J. Tan and F. Wang, “Theoretical analysis and property study of optical focus detection based on differential confocal microscopy,” Meas. Sci. Technol. 13, 1289-1293 (2002).
[CrossRef]

Micron

C. J. R. Sheppard, “Fundamentals of superresolution,” Micron 38, 165-169 (2007).
[CrossRef]

Opt. Express

Opt. Lett.

Other

http://www.pi-china.cn/pdf/pdf/PI_Piezo_NanoPositioners_Section.pdf.

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Figures (8)

Fig. 1
Fig. 1

Composition of IDCM. PBS, polarizing beam splitter; BS, beam splitter.

Fig. 2
Fig. 2

Ultrahigh SNR obtained in IDCM.

Fig. 3
Fig. 3

SNR performance of CM, DCM, and IDCM.

Fig. 4
Fig. 4

Axial response experiments of IDCM.

Fig. 5
Fig. 5

Comparison on reflectance disturbance resistibility between DCM and IDCM.

Fig. 6
Fig. 6

Photograph of the ceramic sample fabricated by laser writing.

Fig. 7
Fig. 7

Partial scanning profile of the area A ( NA = 0.25 ) .

Fig. 8
Fig. 8

Partial scanning profile of the area B ( NA = 0.25 ) .

Equations (6)

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I 1 ( v , u , u M ) = | [ 2 0 1 e i u ρ 2 2 J 0 ( ρ v ) ρ d ρ ] [ 2 0 1 e i ( u + u M ) ρ 2 2 J 0 ( ρ v ) ρ d ρ ] | 2 ,
I 2 ( v , u , u M ) = | [ 2 0 1 e i u ρ 2 2 J 0 ( ρ v ) ρ d ρ ] [ 2 0 1 e i ( u u M ) ρ 2 2 J 0 ( ρ v ) ρ d ρ ] | 2 ,
| 2 0 1 e i u ρ 2 / 2 ρ d ρ | = | 2 i u ( e i u 2 1 ) | = | 2 i u e i u 4 ( e i u 4 e i u 4 ) | = | sinc ( u 4 π ) | ,
I 1 ( u , u M ) = sinc 2 ( u / 4 π ) · sinc 2 ( ( u + u M ) / 4 π ) ,
I 2 ( u , u M ) = sinc 2 ( u / 4 π ) · sinc 2 ( ( u u M ) / 4 π ) .
I ( u , u M ) = n m · ( I 1 + n a ) n m · ( I 2 + n a ) n m · ( I 1 + n a ) + n m · ( I 2 + n a ) = I 1 I 2 I 1 + I 2 + 2 n a = sinc 2 ( ( u + u M ) / 4 π ) sinc 2 ( ( u u M ) / 4 π ) sinc 2 ( ( u + u M ) / 4 π ) + sinc 2 ( ( u u M ) / 4 π ) + 2 n a .

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