Haas Technology, Flanders, N.J., has introduced a patent pending (USPTO 12/756,642) optic design that passively compensates thermal lensing of high power collimators and focusing lenses. Using special optical materials and optic design, thermal lensing for lasers with powers in excess of 1 kW is reduced to less than the Rayleigh range of the lens design.
The TLC Objective™ incorporates balancing the temperature coefficient of refractive index (dn/dT) between two or more optical materials, optimizing thicknesses, air spacing, and curvatures to mitigate thermal lensing, regardless of temperature. The TLC Objective stays in focus from the moment the laser is first turned on to when it is turned off.