As IADIY's expertise and manufacture experience in Laser Optics, we released the laser collimating lenses or called laser collimator, laser diode collimator for R&D and engineering development. We design and manufacture custom and pre-engineered collimating lenses for meeting customers’ application requirements. For some projects like laser collimator and beam expander with the need of fast turnaround time, we can provide many different standard laser collimating lenses with different diameters, focal lengths, coatings, and mounting sizes.
Since the laser diode's output light is highly divergent, it requires the use of collimating lens. Generally, choose aspheric lens reducing the spherical aberration for better collimated beam. Here's an example of the major specifications to consider for choosing the right lens for a given application.
Gaussian beam width w(z) as a function of the distance z along the beam.
Knowing from the laser diode specification sheet, the typical horizontal and vertical divergence angles are 10° and 30° (FWHM), so an elliptical beam is formed as the light diverges. In order to collect as much light as possible during laser collimation, a larger divergence angle (30° in this case) should be used in the calculation. The NA(angle) of the collimating lens should be bigger than the NA(angle) of the laser diode.
For example: 0.30 = NA of Lens> NA of Diode ≈ sin (15°) = 0.26.
The shape of a Gaussian beam of a given wavelength λ is governed solely by one parameter, the beam waist W0 is a measure of the beam size at the point of its focus where the beam width W(z) is the smallest. More introduction can refer to Wiki Gaussian Beam, or YouTube: Gaussian beam introduction.