Light microscopy and adaptive optics, my uncensored and biased opinions

Shack-Hartmann wavefront sensor is a brainchild of Cold War, born in late 1960-s by the need of US Air Force "to improve the images of satellites taken from earth"  -guess who's satellites caused such intense interest of Uncle Sam. The working principle is simple and elegant - the wavefront sampled by an array of micro-lenses, and its local slope is converted into displacements of focal spots: To make an SH sensor today, one needs an array of microlenses and a digital camera. The main difficulty is accurate calibration and the software which will convert camera images into wavefront reading. Thorlabs sells reasonably priced SH sensors and I purchased the WFS-150-7AR for my project. The good It is well built, comes with plate adapter and a C-mount ring adapter. The software runs smoothly and produces expected results (flat wavefront) when tested on spatially filtered and collimated HeNe laser. The manual is very detailed, and API comes in C, C#, and LabVie...

Gaussian beams    is a beautiful phenomenon in optics. As they propagate through space they retain their Gaussian shape, and only get broader or narrower. They are symmetric along the optical axis. No matter how many lenses you use to focus and defocus your laser beam, it will remain Gaussian. And it's shape is described by a few simple formulas , which define their thinnest section (w 0 , 'waist'), radius of wavefront (R), and divergence angle (Theta). Some immediate applications include fiber coupling, confocal microscopy, and light-sheet microscopy. The formulas describing Gaussian beams were derived in the 1960-s, soon after the invention of lasers, by solving the wave equation for electromagnetic waves, and were analysed exhaustively in paraxial approximation (Kogelnik and Li, 1966). Paraxial approximation means that angle of beam divergence angle is small (theta ~ tan(theta)). However, modern microscopy pushes limits to high-NA objectives and laser beam...

Mirao52e  from Imagine Optic is probably one of the best known high-stroke deformable mirrors (DMs), a working horse in adaptive optics. It has 52 actuators , huge stroke (up to +/- 50 microns peak-to-value), and a hefty 15-mm clear aperture of usable mirror surface. All things look good, at a price tag of about 20K euro . After some hesitation and comparing specs/price with Alpao mirrors, I eventually chose Mirao52e for my adaptive optics project. It is too early to speak of performance, I will do optical tests later. Today I can only share my first impressions. Pros: Small form factor: 64x64x17.6 mm, easy to integrate if your space is tight Very easy installation (Windows 7), basically installation of USB-serial port drivers  Cons: Mounting options are weird. There are two M3 tapped holes on each side, 20 mm apart. Does not fit any Thorlabs mount I know - they normally use M4 screws and 25-mm space between. No adapter included :( ...