Femtosecond laser ablation processing of x-cut LiNbO3 substrates for optical communication devices

Riichi Kitano, Kazue Ozono, Minoru Obara, Hiroyuki Tsuda

Research output: Contribution to journalConference article

Abstract

We have studied femtosecond laser ablation characteristics of LiNbO3 for the first time. LiNbO3 is ferroelectric material with large optical nonlinearity and Pockels effect. The femtosecond laser ablation is very useful to fabricate various optical devices including the optical modulator and the tunable optical filter for optical communication systems because the thermal damage around the irradiated area is small due to the short pulse width, and the sub-wavelength structures may be formed by the multi-photon excitation. In our experiments, the femtosecond Ti:Sapphire laser system (Energy 0.14 mJ/pulse, Wavelength 800 nm, Pulse duration 60 fs, Repetition rate 1 kHz) based on the chirped-pulse amplification (CPA) technique was used. The aperture with a diameter of 5 mm was imaged onto the LiNbO3 surface by the objective lens in the air. We observed ablation holes by the scanning electron microscope and the profilometer. We have found no damage around the holes and the clear boundary between ablated area and non-ablated area was observed. Those features are very useful for precise material processing. The bottom face of the holes was relatively flat. The etching rate was 0.93 micrometer/pulse and proportional to the number of the laser pulse. The results showed that the femtosecond laser ablation is an innovative tool for manufacturing LiNbO3-based optical devices.

Original languageEnglish
Pages (from-to)386-393
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume4977
DOIs
Publication statusPublished - 2003 Dec 5
EventPROCEEDINGS OF SPIE SPIE - The International Society for Optical Engineering: Photon Processing in Microelectronics and Photonics II - San Jose, CA, United States
Duration: 2003 Jan 272003 Jan 30

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Keywords

  • Ablation
  • Femtosecond laser
  • LiNbO
  • Optical communication
  • Optical waveguide
  • Processing

ASJC Scopus subject areas

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

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