I just got a few of those 150mW/642nm diodes, which are characterized by “single longitudinal mode” in their data sheet. There was a special price for them during this months; and also a group buy at photonexicon.com.
Obviously of potential interest to holographers…the warm color would be well suited for color holography, and it would work well with optics intended for HeNe lasers such as waveplates.
I immediately ran tests on one of them, with disappointing results at first, but subsequent more careful tests revealed single mode regions at high power and low temperatures, see here. This now seems very promising and I will test more of those diodes, also in ECDL setups – stay tuned.
PS 09.09.09: I found, not unexpectedly, that the HL6385 does fine in an ECDL setup, for details see here.