Tunable Lasers

The basics of tunable lasers

Tunable lasers are laser light sources designed to emit coherent light at large range of wavelengths.  Simply put, this ability to “tune” wavelenghts makes these lasers particularly useful in many applications requiring great flexibility and performance optimization. As such, tunable lasers are commonly used for spectroscopy, interferometry, microscopy applications and writing of Holographic Optical Elements (HOE). More recently, we have seein their rise within quantum research. The basics of tunable lasers involve understanding key principles and mechanisms, including the gain medium (gases, liquids or solids suitable for the emission and amplification of laser light), materials for nonlinear wavelength conversion, wavelength-selective elements (such as diffraction gratings, prisms, or tunable filters), external cavity design and feedback mechanisms for stability.

The challenge of tunability

There exist various types of tunable lasers, each achieving tunability through distinct mechanisms. While these lasers offer notable advantages, attaining and maintaining precise and reliable tunability poses challenges. For instance, one common issue with tunable lasers is ttheir tendency to mode hop, which is the jump between wavelengths as the user attempts to tune the laser. However, aside from mode hopping, other issues that should be accounted for when o