Laser Beam Shaping
Laser shaping applications such as intra-cavity beam shaping, extra-cavity beam shaping, and optical communication benefit greatly from solutions based on adaptive optics. For example, in the field of optical communication, “free-space communication” technology holds exciting potential as a new method for data transmittal without wires or fibers. A small number of commercial systems currently provide this technology, but at a limited range of ~1km. When sending data over longer distances, atmospheric turbulence begins to distort the laser beam, severely limiting the achievable data rate. Adaptive optics allows for the compensation of this atmospheric distortion, providing a much-needed high-speed, long range data link.
As proven in 2004 by Baker, et. al. of Lawrence Livermore National Laboratory, adaptive optics-enhanced free-space laser communication can now travel over 1.35 km (round-trip) in a desert-like climate with high atmospheric distortion. When using the BMC Kilo-DM to correct for distortion, LLNL demonstrated 8X signal improvement.
Laser Pulse Shaping
Laser pulse shaping applications require an active optical element, such as liquid crystal modulators (LCMs), to condense optical spread into ultra-short (femto-second) optical pulses. Recently, MEMS deformable mirrors emerged as a novel alternative that may hold significant advantages over LCMs, such as:
- Optical efficiency: LCMs typically perform with low transmissivity over wide wavelength ranges due to their wavelength selective nature. In contract, deformable mirrors with gold or aluminum coatings can offer more than 90% reflectivity over various wavelength ranges.
- Wavelength independence: an individual MEMS deformable mirror can perform in multiple wavelengths, taking the place of several highly-wavelength dependent LCMs.
- Cost: while individual deformable mirrors and LCMs are currently comparable in cost, MEMS bulk fabrication methods provide large economic benefit for future, high volume applications.