Laser diode collimators of type 96CR, use CircuLaser diodes (Blue Sky Inc.) with integrated micro-optics. The micro-optics transform the elliptical radiation emitted by the laser diode into circular radiation with a deviation maximum of 1:1.2.
The divergent light of the laser diode is transformed into a collimated beam, while maintaining the Gaussian intensity distribution and the circular intensity profile. From the two emission angles θ⊥ and θ|| of the laser diode and the focal length of the collimation optics, the orthogonal and parallel divergence angles and beam diameter can be determined, which are a function of the laser diode used for the collimation.
The new low noise laser diode modules from Schäfter+Kirchhoff have reduced power noise, reduced coherence length and low speckle contrast as a result of internal RF-modulation. The low noise (<0.1% RMS, @<1 MHz) and the mode-hopping free laser operation makes these laser diode modules ideal for particle measurements or advanced medical and biotechnological applications. Due to the reduced coherence length, speckle contrast might be lowered. This effect, however, becomes smaller for smaller spots.