What role do magnets play in laser beam combiners?

What role do magnets play in laser beam combiners?
The magnetic field can have some effects on the laser, mainly in the following aspects: 1. Wavelength modulation: Applying a magnetic field through the permanent magnet group can change the wavelength of the laser. This is because the magnetic field generated by the permanent magnet group affects the electronic energy level structure in the laser medium, thereby changing the emission frequency and wavelength of the laser. 2. Polarization modulation: The magnetic field generated by the permanent magnet group can also affect the polarization state of the laser. Through the magnetic field generated by the permanent magnet group, the polarization direction or polarization intensity of the laser can be changed, thereby realizing polarization modulation. 3. Modulation speed: The magnetic field generated by the permanent magnet group can also be used to modulate the pulse width and pulse repetition frequency of the laser. The temporal characteristics of the laser pulse can be controlled by adjusting the magnetic field strength of the permanent magnet group or by switching the magnetic field rapidly. 4. Optical path deflection: using the magnetic field gradient effect of the magnetic field generated by the permanent magnet group, the laser beam can be deflected. This can be applied to optical devices, optical communication systems and other fields to realize the adjustment and control of light beams.