[OPTICAL REVIEW Vol. 10, No. 1 (2003) 19-23]
© 2003 The Optical Society of Japan

Spectral Intensity Distribution of a Time Dependent Gaussian Pulsed Beam From a Circular Aperture in the Near-Field Diffraction

Gwo-Huei YANG*, Hone-Ene HWANG and Pin HAN1

Department of Electronic Engineering, Chung Chou Institute of Technology, Yuan-lin 510, Taiwan, R.O.C.

1Department of Electrical Engineering, Da Yeh University, Da-Tsuen 515, Taiwan, R.O.C.

(Received December 25, 2001; Accepted October 22, 2002)

The diffraction characteristics of a broadband light source from a circular aperture in the near-field are clarified theoretically via prompt and precise mathematical derivation. This paper provides a explicit way of treating in the case of time dependent Gaussian-shaped pulsed beam passing through a circular aperture and gives more accurate and concrete criteria for judging the timing of the spectral red shift, blue shift and splitting of light distributions. Furthermore, the results offer an understanding of the Gaussian beam quality of the output of an optical resonator in the near-field.

Key words: Gaussian-shaped pulse, duration time, near-field diffraction, circular aperture, spectrum bandwidth, spectral intensity, Fresnel diffraction integral, Lommel-function