Tunable lasers is a field of study and technological development concerning laser systems engineered to emit coherent radiation with a precisely controllable output wavelength or frequency across a designated spectral range. This domain investigates the optical physics and engineering approaches enabling such spectral agility, including novel gain materials, cavity designs, and tuning elements, and explores their performance characteristics and critical applications in areas like high-resolution spectroscopy, atmospheric sensing, medical diagnostics, and fundamental physics experiments.