Photostimulated Luminescence: Calcium Sulfide in Salt - Green vs. Red Laser


This shows the photoluminescence of CaS:Mn2+,Pb2+ in salt a few minutes after being charged with UV light and exposed to a green 532nm and a red 650nm laser. The sequence flows from left to right, the green laser is the upper sequence, the red laser is the lower. The first image shown is the CaS disc after exposure to UVabc in its phosphorescent state and after being exposed to some prior laser flashes to darken the specimen. The images were taken about a minute apart with the exposures being 15 seconds long.

Before the center images were taken, the laser was moved a few times (horizontally for the green, and vertically for the red).

The lasers caused an immediate flare in brightness followed by darkening of the phosphorescent glow. The flare created by the green laser was brighter and persisted longer than the flare created by the red laser. The darkening created by the red laser was darker.

The green laser appears to have "recharged" the phosphor a bit in addition to producing the PSL flash and darkening. This can be seen in the last image of the green laser sequence as a slighly orange glow on the darkness.

Contains:
CaS:Mn2+,Pb2+ (FL+PHOS Orange! >UVabc)

Shown in phosphorescent state a few minutes after exposure to UVabc light and after exposure to green and red laser light.

Key:
WL = White light (halogen + LED)
FL = Fluoresces
PHOS = Phosphorescent
Blue = 450nm,
UVa = 368nm (LW), UVb = 311nm (MW), UVc = 254nm (SW)
'>' = "stimulated by:", '!' = "bright", '~' = "dim"

Original CaS exeriment:
www.flickr.com/photos/28617364@N04/sets/72157636424108354/

Series best viewed in Light Box mode using Right and Left arrows to navigate.
Photostream best viewed in Lightbox mode (in the dark).

18 Watt Triple Output UV lamp from Polman Minerals - Way Too Cool UV lamps

Flickr page for this photo.

Visit the Eye for Science Flickr group.

Get the "Eye for Science" widget here and install it on your own blog. Spread the scienticity!

Like this image? Want it for your smartphone wallpaper?
Use this QR Code to load it on your smartphone and enjoy!