Source: MDPI

Intracavity Pumping in Lasers

Introduction

Intracavity pumping is a technique used in laser technology where the gain medium of a laser is placed inside the resonator of the pump laser. This method offers advantages in cases where traditional pumping methods may be inefficient.

Application in Bulk Lasers

Bulk lasers, composed of discrete elements like laser crystals and mirrors, are commonly used with intracavity pumping. By placing the gain medium inside the laser resonator, higher intracavity power can be achieved compared to using an output coupler mirror. This setup is particularly suitable for high pump absorption in the second crystal.

Intracavity Pumping Setup

Typically, the pump laser is powered by laser diodes, with the radiation being coupled into the system through dichroic mirrors. Vertical external-cavity surface-emitting lasers can also be used for intracavity pumping, with special considerations for reflector integration.

Applications in Other Laser Systems

Intracavity pumping is not limited to bulk lasers and can be applied in optical parametric oscillators (OPOs) and Raman lasers, especially for continuous-wave operation where high pump power is crucial. The interplay of two lasers in the system can lead to unique laser dynamics, including relaxation oscillations.

Examples of Intracavity Pumping

One example involves using an ytterbium-doped laser gain medium pumped at 914 nm with a Nd:YVO₄ laser for efficient operation. Another example is the in-band pumping of holmium lasers with 2-μm radiation from a thulium laser within a Tm:YLF or Tm:YAG laser resonator.

Conclusion

Intracavity pumping offers a compact and efficient solution for laser systems that require high pump power and where traditional pumping methods may not be optimal. By integrating the gain medium within the laser resonator, higher intracavity power can be achieved, leading to improved laser performance.

Source: MDPI
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