Looky what I found. Is it true? Looking around it seems there was such a laser sold in this form, but no longer is except here maybe. search 552nm laser pointer.
The New Upgrade 552nm Green Laser Pointer Pen Adjustable Focus 532nm Lazer Visible Beam Laser Pointer Astronomy Laser Pointer Buy From Laser666888, $23.12| Dhgate.Com
552nm Laser Pointer from China - 552nm Laser Pointer from Chinese 552nm Laser Pointer Store at Laser666888 | DHgate.com
Cool, but I wonder how 'worth-it' this would be. 561nm is yellow enough to be a really interesting color. Seems like 552nm would be a lot closer to 532nm. Maybe if it was a lot cheaper than 561nm it would be nice.
I thought I read somewhere on here that it was a doubled 1104nm diode. Not aware of any Nd lines at 1104nm.
Here is how one group did it back in 2012:
"A high-power diode-side-pumped 1,105 nm Nd:GGG laser and a laser at 552 nm based on intracavity frequency doubling of 1,105 nm laser are demonstrated for the first time. A 26.8-W 1,105 nm laser continuous wave output was achieved under the incident pump power of 170 W. A LiB3O5 crystal is used for second harmonic generation of 1,105 nm laser. When the pump power was 170 W, the average output power at 552 nm of 7.3 W was obtained, corresponding to the optical conversion efficiency of 4.3 %. And the minimum pulse width is 181 ns with the pulse repetition rate of 10 kHz. The M2 factors are measured to be 19.8 and 17.6 in the horizontal and vertical directions, respectively."
Article is here: Diode-side-pumped Nd:GGG laser at 1,105*nm and frequency-doubled laser at 552*nm - Springer
Well, with a quick look through ye auld Handbook of Laser Wavelengths it appears that Nd:YAG has a line at 1105nm. Though the paper was published in 1968, and I can't seem to find any other sources to back that up. But, while searching for the source, I found that Nd:GGG actually lases 1104nm with reasonable efficiency.
EDIT: Looks like Encap beat me to it.