Optical DIY High resolution spectrometer

[Pyrolytic]

TL;DR Summary

Help in modify a BW tek BTC100-2s spectrometer to improve its resolution while decreasing the spectral range.

Hello All,

I recently purchased a BW Tek BTC100-2s spectrometer from eBay. It has fairly good specifications, but I have been wondering if there is an inexpensive way to improve its resolution. The spectrometer uses a Czerny-Turner configuration. My plan was to place a slit at the focal length where the detector (F) would be, then expand that narrow section of the spectrum to fill the detector. However, I have been struggling with how to efficiently expand and focus the light after the slit onto the detector. Here are some of the specs for the spectrometer:

• Spectral range: 400-640nm
• Slit size: 50µm
• Grating: 1800 lines/mm, blazed at 500nm
• Detector: Sony ILX511 2048 Pixel CCD
• Pixel spacing: 14µm
• Pixel size: 200µm

Any advice or suggestions would be greatly appreciated.

 

[Tom.G]

Maybe use a different grating? One with a wider dispersion.

Or replace mirror "E" with one of different curvature (or even flat?). This would spread out the spectrum that falls on the detector.