Principles of Femto-second Lasers and Recent Technology Trends

Abstract

This article provides an overview of the principles of ultrashort pulse lasers and current research trends, targeting users of femtosecond lasers for visualization purposes. Femtosecond lasers, now commercially available, are increasingly compact and widely adopted in visualization techniques. Despite their ease of use, they often do not reach their full potential as light sources. To address this, a fundamental understanding of femtosecond laser pulse generation is essential. This article quantitatively presents these fundamentals using easily understandable charts and graphs. In the latter part, recent trends in generating ultra-short pulses are introduced. Previously, oscillators primarily generated the shortest pulses in laser systems. However, contemporary approaches incorporate techniques such as nonlinear pulse compression from longer pulses, the concept of time lenses, and electrical modulation of continuous waves to achieve shorter pulses. These concepts are elucidated in a manner conducive to a thorough grasp of the basics.