| 摘要 |
Embodiments of the invention describe an illuminator having a light source to originate an illumination beam, wherein the light source further comprises a set of vertical- cavity surface emitting lasers (VCSELs) (102) including a first VCSEL (401) having a first laser emission wavelength (405), and a second VCSEL (402) having a second laser emission wavelength (406) different than the first laser emission wavelength. Thus, by varying laser emission wavelengths of VCSELs in a VCSEL array, embodiments of the invention produce low- contrast speckle, and do not limit the imaging capabilities of the host illumination system. In some embodiments of the invention, vertical external cavity surface emitting lasers (VECSELs) are utilized to produce the above described varying laser emission wavelengths. The VCSEL may be on a single chip with wavelength variation due to a variation of the thickness of a spacer layer (511-514) between the two DBR's within the cavity of the VCSEL, i.e. by changing the cavity length. |
