Abstract

The beam radius along a focused, unapertured Gaussian beam was measured and used to calculate the dependence of the geometrical Fresnel number on the effective Fresnel number of the beam as it emerged from the focusing lens. The resulting data clearly demonstrate a focal shift away from the focal plane given by geometrical optics. The data agree very well with a theory due to Carter. This theory indicates that a significant focal shift occurs in these beams if the focusing lens is placed within the near field of the focal plane.

© 1984 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Focal shift and concept of effective Fresnel number for a Gaussian laser beam

William H. Carter
Appl. Opt. 21(11) 1989-1994 (1982)

Focal shift in Laguerre–Gaussian beams

William H. Carter and Maurice F. Aburdene
J. Opt. Soc. Am. A 4(10) 1949-1952 (1987)

Propagation equation of Gaussian beams through apertured focusing systems and parametric study of focal shift

Peng Sun, Ji Liu, Jinge Guan, Gao Wang, and Yang Yu
J. Opt. Soc. Am. A 36(5) 818-825 (2019)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (3)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (5)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription