通过改换激发材料,科学家能造出以不同波长发射的激光器,案例如下所示。固态激光:第一台红宝石激光是固态激光器的例子。此时,红宝石晶体发射的是694纳米的红光波长。固态激光器如今经常以玻璃或水晶制作,后者还要掺杂一些稀有元素。其中有一种是用掺钕的钇铝石榴石晶体制作,能发射1064纳米波长的红外光。 By changing the excitation material, scientists can create lasers that emit at different wavelengths, as shown below. Solid State Laser: The first ruby ​​laser is an example of a solid state laser. At this point, the ruby ​​crystal emits a red wavelength of 694 nanometers. Solid-state lasers are now often made of glass or crystal, which is also doped with some rare elements. One of them is made of neodymium-doped yttrium aluminum garnet crystals that emit infrared light at 1064 nm.