Hi guys!

Is there any interest in L/2 achromatic waveplates?
The advantage of achromatic waveplates is that they can be used for a wide wavelength range. Standard waveplates are suitable for narrow spectral ranges (XXXnm +/- 15nm or less). Achromatic waveplates can cover almost the entire VIS range. I got a quotation for 10mm round or 11x11mm square waveplates for a 430-665nm range.
They are more expensive as single wavelength waveplates but may save money and space inside the module on the other hand. For example, when you build a dual wavelength module doubling each color with a pbs, you have four diodes and need two waveplates and two pbs cubes. With an achromatic waveplate you can just combine two colors with a dichroic mirror and shoot the beam directly through the pbs. For the second diode pair you place the waveplate between the dichro and the PBS.

Details:

material quartz and MgF2
optical contacted for high power
size 11x11mm or 10mm +0/-0.2mm
retardation L/2 for 430-665nm (tolerance < L/100)
both sides AR coated
Price: 60€