As we know, multi-mode laser diodes generally have worse specs than their single-mode counterparts. For example, the specs of most multi-mode 650 nm diodes are something like 5 mrad at 5 mm.
However, the recent 445 nm diodes seem to have much better specs, even though they are also multi-mode. Does anyone know what's so special about those diodes? I know that lasers with shorter wavelengths generally have better specs, but I don't think a difference 200 nm would have that much of an impact. I've heard that laser diodes can be multi-mode in two ways (lateral and transverse), but I have no idea what the difference is.
Also, DPSS lasers generally have very good specs, even though they are pumped by multi-mode diodes. What exactly do DPSS lasers have that diode lasers don't, aside from crystals?
However, the recent 445 nm diodes seem to have much better specs, even though they are also multi-mode. Does anyone know what's so special about those diodes? I know that lasers with shorter wavelengths generally have better specs, but I don't think a difference 200 nm would have that much of an impact. I've heard that laser diodes can be multi-mode in two ways (lateral and transverse), but I have no idea what the difference is.
Also, DPSS lasers generally have very good specs, even though they are pumped by multi-mode diodes. What exactly do DPSS lasers have that diode lasers don't, aside from crystals?