Here is a history of public lab spectrometer research ideas up to the present. There is really no analysis here, just a catalog.
relationships between spectrometer components
cfastie's also investigated slit width and the relationship between the distance between the slit and the grating to produce some charts on the relationship.
the beginnings of UV Fluorescence research are Warren's, and Alex McCarthy picked up on warren's research and provided a number of peer-reviewed papers on the subject of UV Spectroscopy.
Alex McCarthy also began doing UV fluorescence on laundry detergents. JoshMC's note on UV fluorescence was a replication and expansion of Alex's research
Jeff Warren kicked off the spectrometry project as a means to do oil identification, and the beginnings of our contemporary UV fluorescence kit can be seen in his late 2010-early 2011 notes along with research to determine if hydrocarbon identification would be possible with low cost CMOS, or CCD -based hacked devices.
An interesting direction explored by Alex was using a DVD as a reflective grating instead of a transmission grating.
to quote: "Aside from not filtering UV light, the reflective grating spectrometer seemed to have a few other advantages: Because the light source was not in the line of sight of the camera, there was little or no glare in the spectrum."
Alex helped produce the our first guide to building a spectrometer.
After originating the spectrometry project and a year after starting to play with CD spectrometers warren posted a tutorial that really kicked off community research.Warren's awesome VHS box spectrometer, which he based on a series of cool educational workshops, such as this solar physics lab from NOAA and Simon Quellen Field's Scitoys spectrometer build. There are many tutorials on CD/DVD spectrometers out there, these are just two of the better examples.
second generation designs
In order to make the spectrometer play nicely with add-ons and attachments, warren settled on a type LB conduit box as a better housing.
This model depended on the easy to mount and rectangular Syba camera. When that camera went out of production in 2013, mathew modified the design to use a "gumstick" camera, the standard size of usb webcam found in laptops, right above the screen. This required the introduction of a 45 degree wooden block, and is a desktop spectrometer 2.5.
cfastie also had a great series of mods for mounting a fold-up spectrometer to an iphone.
Homechemist has an interest in fluorescence and raman spectroscopy and created a reflectance spectrometer similar to Alex McCarthy's, only enclosed in a box. homechemist used two built-in lasers for calibration and fluorescence testing:
collimation slits/smartphone spectrometer
For most of the spectrometer's history, we've used hand or laser cut paper as the slit. Some people have followed the NOAA instructions to create razor blade slits. Stoft saw the slit as a means to achieve some level of intensity calibration and to use high dynamic range (HDR) techniques to get more precise measurements. He began printing his own slits on acetate using a laser printer, as an alternative to lens filters that attenuate light. There are a lot of advantages to hdr, as stoft has pointed out. His printed slits didn't return very good results, though. Still, it was an interesting concept, and warren mentioned it to mathew who went and printed slits using photoprinting, whereby silver nitrate is deposited on acetate. This technique was integrated into the smartphone spectrometer for its clarity. That slit is .09mm in thickness, a thickness which is debated for the amount of light it passes.
beginnings of a third generation
RTegelbeckers wanted a box that was flatter, and easier to put together (after he 3d printed it).
Holding samples in the right place is a big demand for a new spectrometer, Dusjagr to have a cuvette holder.
Warren and cfastie envisioned a 3D printed cuvette holder.
Mathew made a pattern for cutting the spectrometer box to accomplish a similar task.
This idea of using droplets instead of cuvettes is a very contemporary idea, similar to a "nanodrop" commercial spectrometer. Gaudi made this DIY version. There are a variety of out-of-patent methods of using droplets that mathew put in gaudi's comments.
Analysis & Activities
Things I found, not complete ideas.