Thomas, John and Alti, Kamlesh and Dharmadhikari, JA and Santhosh, Chidangil and Mathur, D (2013) Pattern formation in transparent media using ultrashort laser pulses. Optics Communications, 304 (1). pp. 29-38. ISSN 0030-4018

PDF Pattern formation _ Opt. Communication.pdf - Published Version Restricted to Registered users only Download (6MB) | Request a copy

Abstract

We report results of a systematic study of the morphology of laser-written structures within transparent media like fused silica, borosilicate glass (BK7), and polymethylmethylacrylate (PMMA) using a high-energy, 5.1 MHz repetition rate, femtosecond laser oscillator. Depending on experimental conditions, both smooth channels as well as dot patterns can be laser-written. The periodicity of the written dots is readily controlled by the energy dose, a single parameter that encompasses laser energy, translation speed at fixed repetition rate, and focusing conditions. We discover the importance of the direction in which laser-writing is carried out: the periodicity of the dot patterns written at fixed energy dose but with opposite writing directions is significantly different. In PMMA, extremely large rod-like structures (∼200 µm) are observed whose formation is also dependent on writing direction. We quantify guidance of 632 nm and 830 nm light in structures written in BK7.

Actions (login required)

View Item