Spectroscopy Lab

Approaching the summer solstice, the start of fall-semester classes and their attendant labs seems far away, but a new class of St. Lawrence first-year students will be here before I know it.

Spectroscopy Lab I

This was one of the light sources students were interrogating: a sodium lamp, like the ones used in street lights (at least in the twentieth century—LED street lamps are becoming increasingly dominant now.)

Spectroscopy Lab II

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532 nm

In St. Lawrence’s Raman spectroscopy and microscopy lab, the most potent laser illumination source comes from a neodymium-doped yttrium aluminum garnet. This is a pretty ubiquitous laser source, but I happen to like it because it also demonstrates the value of nonlinear optics: though this laser is emitting light at 1064 nanometers (in the infrared), a suitable doubling crystal can combine two of those 1064 photons together to make a shiny new 532 nm photon.

532 nm

This Is the Laser

The laboratories of physical scientists across the planet have pulsed laser systems like this one, and many look quite similar: a collection of squat boxes covering optics, electronics, and beampaths. Above or below the surface of the table are additional boxes of electronics driving the lasers and detectors. This particular system is special to me for two reasons: (1) most modern laser tables don’t have rad wood grain paneling, and (2) this was the instrument I used during my sabbatical at Berkeley Lab last spring. Lots of good data emerged from its photomultiplier tube.

This Is the Laser

Spectroscopy Lab

After spending my entire adult life as a laboratory scientist, the web of gas lines and vacuum pumps and electrical cable seems normal. I do understand, rationally, that all of this looks overwhelming. There’s so much purpose and productivity behind the network, however, that it’s worth the sophistication.

Spectroscopy Lab