There are many ways to achieve dual wavelengths, and solid-state lasers usually share part of the resonator through beam splitting, and the length or polarization of two different resonators is inconsistent, and the mode selection output is inconsistent, so the output of dual wavelengths is inconsistent. In fiber lasers, it is usually achieved by reflecting two or transmitting two center wavelengths through optical fibers. Because of the shared resonator, the power will affect each other. This is called a dual-wavelength laser.

Dual-wavelength lasers are available in a variety of designs to output adjacent or non-adjacent laser wavelengths. For example, the in-line type uses two semiconductor lasers of different wavelengths to be mechanically connected together, and optical lenses can also be used to change the shape of the laser spot, such as infrared lasers for electrical energy measurement and red lasers for the human eye.The other is the coupling fiber bundle type, which can break through the limit of a single semiconductor laser by using the dual-wavelength laser output synthesized by the coupled fiber, making this technology widely used in high-power, multi-band output occasions.

Applications of dual-wavelength lasers

Dual-wavelength lasers have a wide range of applications in interferometric rainbow holography, fine laser spectroscopy, differential absorption lidar, multiphoton stepwise ionization of atoms and molecules, nonlinear frequency transformation, laser medicine, and military. For example, in the case of high-brightness laser color displays, it can be used as a light source for color LCD displays or color LCD TVs. In terms of laser color printing, it can be used as a light source for high-brightness laser color printers. In the entertainment industry, it can be used as a light source for laser color screens and film projection systems.