Effect of spot size, pulse energy, and repetition rate on microsecond ablation of gelatin under water

Ujwal S. Sathyam; Alan Shearin; Scott A. Prahl

doi:10.1117/12.209900

22 May 1995 Effect of spot size, pulse energy, and repetition rate on microsecond ablation of gelatin under water

Ujwal S. Sathyam, Alan Shearin, Scott A. Prahl

Proceedings Volume 2391, Laser-Tissue Interaction VI; (1995) https://doi.org/10.1117/12.209900
Event: Photonics West '95, 1995, San Jose, CA, United States

Abstract

The efficiency of laser ablation of thrombus depends on spot size, pulse energy and repetition rate. A 1 microsecond(s) pulsed dye laser (504 nm) was used to ablate a gelatin-based thrombus model containing an absorbing dye under water. The gelatin was confined in 3 mm inner diameter tubes and pulse energies of 25-100 mJ were delivered via 300, 600, and 1000 micrometers core diameter fibers. The experiments were conducted at pulse repetition rates of 3 Hz and 10 Hz. The amount of gelatin removed was measured using a spectrophotometric method and ablation efficiency was defined as mass removed per pulse per unit energy. Flash photography was used to visualize the ablation process in 1 cm cuvettes. Results: More material was removed using bigger fibers in the 3 mm tubes at similar pulse energies. The amount of gelatin removed per pulse increased linearly with pulse energy. There was no significant change in the amount removed at pulse repetition rates of 3 Hz and 10 Hz. In the 1 cm cuvettes, the ablation mass was roughly the same with both the 300 micrometers and 1000 micrometers fibers. Flash photography of the ablation process in 1 cm cuvettes showed that less than 1% of the laser energy went into formation of a vapor bubble. The mass removed increased roughly linearly with bubble energy. Conclusions: Ablation mass increases linearly with pulse energy, but does not have a direct relationship with radiant exposure. It is independent of the repetition rate under 10 Hz.

Citation Download Citation

Ujwal S. Sathyam, Alan Shearin, and Scott A. Prahl "Effect of spot size, pulse energy, and repetition rate on microsecond ablation of gelatin under water", Proc. SPIE 2391, Laser-Tissue Interaction VI, (22 May 1995); https://doi.org/10.1117/12.209900

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