Resonant Infrared Laser Materials Processing at High Vibrational Excitation Density: Applications and Mechanisms

R. F. Haglund, Daniel-Dennis Bubb, D. R. Ermer, G. K. Hubler, E. J. Houser, J. S. Horwitz, B. Ivanov, M. R. Papantonakis, B. R. Ringeisen, K. E. Schriver

Research output: Contribution to journalConference article

8 Scopus citations

Abstract

As laser micromachining is applied to ever smaller structures and more complex materials, the demand for greater control of the laser energy budget, in space and time, grows commensurately. Here we describe materials modification using picosecond resonant laser excitation in the mid-infrared spectral region to create spatially and temporally dense vibrational, rather than electronic, excitation. Examples include ablation of fused silica and machining of crystalline quartz; deposition of functionalized polymers on microstructures, and laser-directed transfer of proteins and nucleotides from a matrix of water ice. The experiments demonstrate that high spatial and temporal density of vibrational excitation can be achieved by ultrafast resonant infrared excitation of selected vibrational modes of these materials. In some cases, resonant infrared materials modification is far more successful than techniques based on ultraviolet excimer lasers. The laser used for most of the experiments was a tunable, high pulse-repetition frequency free-electron laser. However, a comparison of polymer deposition using a conventional nanosecond laser at a wavelength of 2.94 μm shows that the possibility exists for transferring the concept to conventional table-top devices. Mechanistic considerations nevertheless suggest that ultrashort pulses are likely to be more useful than longer pulses for many applications. A figure of merit is proposed for self-consistent comparisons of processing efficiency among different lasers.

Original languageEnglish (US)
Pages (from-to)13-23
Number of pages11
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume5063
DOIs
Publication statusPublished - Dec 1 2003
EventFourth International Symposium on Laser Precision Microfabrication - Munich, Germany
Duration: Jun 21 2003Jun 24 2003

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Keywords

  • Excitation density
  • Picosecond lasers
  • Resonant vibrational excitation
  • Tunable lasers

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