Ruby Laser

This model shows us one of many types of lasers, a **ruby laser**. A ruby laser is a **solid-state laser**. It uses the ruby crystal as its laser medium. Ruby laser is one of the few solid-state lasers that produce **visible light**.



The most important elements of a ruby laser are **laser medium (ruby), the pump source, and the optical resonator**. In a ruby laser, a flash tube (a gas discharge tube) is used as the energy source or pump source. The flash tube supplies energy to the laser medium (ruby). When lower energy state electrons in the laser medium gain sufficient energy from the flash tube, they jump into the excited state.



The cylindrical ruby rod is placed between two mirrors. The fully silvered mirror will completely reflect the light whereas the partially silvered mirror will reflect most of the light but allows a small portion of light through it to produce output laser light. The light produced within the laser medium will bounce back and forth between the two mirrors. This stimulates other electrons to fall into the ground state by releasing light energy. This is called **stimulated emission**.