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United States Patent 6,433,305
Liu ,   et al. August 13, 2002
Method and apparatus for drilling holes with sub-wavelength pitch with laser

Abstract

A method of laser machining using an ultra-fast pulse laser is presented. According to the present invention a plurality of holes with a pitch less than the wavelength of the laser are drilled into a material sample. Reliable and reproducible hole drilling is accomplished through an exemplary drilling sequence which applies a number of pulses at a first pulse energy to the surface spaced to avoid laser hardening of the surface for adjacent holes of a first set of holes. Next, the number of pulses is increased or the energy of the laser beam is increased to drill holes that are interstitial to the first set of holes. The exemplary laser machining process may used to produce both one-dimensional and two-dimensional photonic crystals, among other applications.

Inventors: Liu; Xinbing (Acton, MA); Li; Ming (Storrs, CT)
Assignee: Matsushita Electric Industries Co., Ltd. (Osaka, JP)
Appl. No.: 747682
Filed: December 26, 2000

Current U.S. Class: 219/121.71; 219/121.69
Intern'l Class: B23K 026/02
Field of Search: 219/121.71,121.69,121.6,121.61,121.67,121.68,121.7,121.78 372/25

References Cited
U.S. Patent Documents
5037183Aug., 1991Gagosz et al.
5280491Jan., 1994Lai.
5409408Apr., 1995Ellingson et al.
5451785Sep., 1995Faris.
5656186Aug., 1997Mourou et al.
5747769May., 1998Rockstroh et al.
5841102Nov., 1998Noddin.
5916462Jun., 1999James et al.
6172331Jan., 2001Chen.

Primary Examiner: Dunn; Tom
Assistant Examiner: Johnson; Jonathan
Attorney, Agent or Firm: Ratner & Prestia
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