Visualizing microair blasts using double-exposure holographic interferometry

Gopalan Jagadeesh; Osamu Onodera; Toshihiro Ogawa; Kazuyoshi Takayama

doi:10.1117/12.424356

17 April 2001 Visualizing microair blasts using double-exposure holographic interferometry

Gopalan Jagadeesh, Osamu Onodera, Toshihiro Ogawa, Kazuyoshi Takayama

Proceedings Volume 4183, 24th International Congress on High-Speed Photography and Photonics; (2001) https://doi.org/10.1117/12.424356
Event: 24th International Congress on High-Speed Photography and Photonics, 2000, Sendai, Japan

Abstract

Micro air blasts are generated over planar and corrugated surfaces, at stand-off distances of 4 and 11 mm, by focusing a 1.38J, 18 ns Nd:Glass laser pulse in a tiny spot of 300 micrometer diameter, under ambient conditions. This triggers the breakdown of air at optical frequencies with subsequent formation of laser plasma, which generates an outward propagating spherical micro-blast wave. The velocity of this wave decreases as time elapses, since the energy deposition is finite, with reference to both space and time. The evolution, propagation and subsequent reflection of the spherical micro- blast wave, from planar and corrugated surfaces are experimentally investigated, using double exposure holographic interferometry. One planar surface and four surfaces with varying degree of surface corrugations are used in this study. Mach reflection of the blast wave is observed at a stand-off distance of 4 mm over a planar obstacle while only regular reflection is visualized at an 11 mm stand-off distance. However only regular reflection is observed at both stand-off distances, in the case of corrugated surfaces.

Citation Download Citation

Gopalan Jagadeesh, Osamu Onodera, Toshihiro Ogawa, and Kazuyoshi Takayama "Visualizing microair blasts using double-exposure holographic interferometry", Proc. SPIE 4183, 24th International Congress on High-Speed Photography and Photonics, (17 April 2001); https://doi.org/10.1117/12.424356

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available