Absolute Distance Measurements Using the Optical Comb of a Femtosecond Pulse Laser

  • Jin, Jong-Han (Billionth Uncertainty Precision Engineering Group, Korea Advanced Institute of Science and Technology) ;
  • Kim, Young-Jin (Billionth Uncertainty Precision Engineering Group, Korea Advanced Institute of Science and Technology) ;
  • Kim, Yun-Seok (Billionth Uncertainty Precision Engineering Group, Korea Advanced Institute of Science and Technology) ;
  • Kim, Seung-Woo (Billionth Uncertainty Precision Engineering Group, Korea Advanced Institute of Science and Technology)
  • Published : 2007.10.01

Abstract

We describe a new way of implementing absolute displacement measurements by exploiting the optical comb of a femtosecond pulse laser as a wavelength ruler, The optical comb is stabilized by locking both the repetition rate and the carrier offset frequency to an Rb clock of frequency standard. Multiwavelength interferometry is then performed using the quasi-monochromatic beams of well-defined generated wavelengths by tuning an external cavity laser diode consecutively to preselected light modes of the optical comb. This scheme of wavelength synthesizing allows the measurement of absolute distances with a high precision that is traceable to the definition of time. The achievable wavelength uncertainty is $1.9{\times}10^{-10}$, which allows the absolute heights of gauge blocks to be determined with an overall calibration uncertainty of 15 nm (k = 1). These results demonstrate a successful industrial application of an optical frequency synthesis employing a femtosecond laser, a technique that offers many possibilities for performing precision length metrology that is traceable to the well-defined international definition of time.

Keywords

References

  1. Ishige, M., Matsuura, F., Kawasugi, M. and Aketagawa, M., 'Phase Modulation Homodyne Interferometer with a 10-pm Resolution Using a Tunable Laser Diode,' International Journal of Precision Engineering and Manufacturing, Vol. 8, No. 2, pp. 80-84, 2007
  2. Jin, J. H., Misumi, I., Gonda, S. and Kurosawa, T., 'Pitch Measurement of 150 nm 1D-grating Standards Using an Nanometrological Atomic Force Microscope,' International Journal of Precision Engineering and Manufacturing, Vol. 5, No. 3, pp. 19-25, 2004
  3. Eom, T. B., Lee, J. Y., Kim, J. W. and Lyou, J., 'Portable Calibration System for Displacement Measuring Sensors,' International Journal of Precision Engineering and Manufacturing, Vol. 7, No. 2, pp. 56-59, 2006
  4. Bobroff, N., 'Recent advances in displacement measuring interferometry,' Meas. Sci. Technol., Vol. 4, No. 9, pp. 907-926, 1993 https://doi.org/10.1088/0957-0233/4/9/001
  5. Kikuta, H., Iwata, K. and Nagata, R., 'Distance measurement by the wavelength shift of laser diode light,' Appl. Opt., Vol. 25, Issue 17, pp. 2976-2980, 1986 https://doi.org/10.1364/AO.25.002976
  6. Fischer, E., Dalhoff, E., Heim, S., Hofbauer, U. and Tiziani, H. J., 'Absolute interferometric distance measurement using a FMdemodulation technique,' Appl. Opt., Vol. 34, Issue 25, pp. 5589-5594, 1995 https://doi.org/10.1364/AO.34.005589
  7. Jin, J., Kim, Y. J., Kim, Y., Kim, S. W. and Kang, C. S., 'Absolute length calibration of gauge blocks using optical comb of a femtosecond pulse laser,' Opt. Express, Vol. 14, Issue 13, pp. 5968-5974, 2006 https://doi.org/10.1364/OE.14.005968
  8. Jones, D. J., Diddams, S. A., Randka, J. K., Stentz, A., Windeler, R. S., Hall, J. L. and Cundiff, S. T., 'Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,' Science, Vol. 288, No. 5466, pp. 635-639, 2000 https://doi.org/10.1126/science.288.5466.635
  9. Ma, L. S., Bi, Z., Bartels, A., Robertsson, L., Zucco, M., Windeler, R. S., Wilpers, G., Oates, C., Hollberg, L. and Diddams, S. A., 'Optical frequency synthesis and comparison with uncertainty at the $10^{-19}$ level,' Science, Vol. 303, No. 5665, pp. 1843-1845, 2004 https://doi.org/10.1126/science.1095092
  10. Udem, T., Reichert, J., Holzwarth, R. and Hansch, T. W., 'Accurate measurement of large optical frequency differences with a mode-locked laser,' Opt. Lett., Vol. 24, Issue 13, pp. 881-883, 1999 https://doi.org/10.1364/OL.24.000881
  11. Siemsen, K. J., Siemsen, R. F., Decker, J. E., Marmet, L. and Pekelsky, J. R., 'A multiple frequency heterodyne technique for the measurement of long gauges,' Metrologia, Vol. 33, pp. 555-563, 1996 https://doi.org/10.1088/0026-1394/33/6/6
  12. Tsai, M., Huang, H., Itoh, M. and Yatagai, T., 'Fractional fringe order method using Fourier analysis for absolute measurement of block gauge thickness,' Opt. Rev., Vol. 6, No. 5, pp. 449-454, 1999 https://doi.org/10.1007/s10043-999-0449-x
  13. Decker, J. E. and Pekelsky, J. R., 'Uncertainty evaluation for the measurement of gauge blocks by optical interferometry,' Metrologia, Vol. 34, pp. 479-493, 1997 https://doi.org/10.1088/0026-1394/34/6/4
  14. Birch, K. P. and Downs, M. J., 'An updated Edlen equation for the refractive index of air,' Metrologia, Vol. 30, pp. 155-162, 1993 https://doi.org/10.1088/0026-1394/30/3/004
  15. International Organization for Standardization, 'Guide to the expression of uncertainty in measurement,' International Organization for Standardization, 1993