| 摘要 |
Laser devices described may emit a beam of electromagnetic radiation having a large wavelength (e.g., mid-infrared, far-infrared) and exhibiting a low angle of divergence. In some embodiments, the wavelength of the electromagnetic radiation is between 3 microns and 500 microns and the divergence angle is less than 15 degrees. Electromagnetic waves may be produced from a single monolithic laser device which includes a laser waveguide (e.g., quantum cascade laser waveguide) and a collimating element having at least one indented region (e.g., a plurality of periodically disposed grooved structures). A portion of the electromagnetic radiation may propagate as surface waves (e.g., surface plasmons) along the surface of the collimating element where indented regions in the collimating element may decrease the propagation velocity of the surface waves. A portion of the electromagnetic radiation may also be substantially confined within a grooved structure of the collimating element (e.g., as channel polaritons). |
