Links to incredibly nerdy and useless stuff that I’ve done for no good reason. Well, as my father would say, ‘the best kind of stuff!’.

How to build an inexpensive spectrometer.

In light of recent events (a teen has won $100,000 for building an inexpensive spectrograph), I decided to post my own version of a cheap spectrograph in a few days. (How sad, I don’t update this much unless teens encourage me to.) Note: This was a report that was dug up from a project I’ve done with colleagues in an undergraduate optics course. I decided to leave the names of team members off of this report for privacy reasons. The report has been truncated in order to retain readership attention.

Specs/requirements of Spectrometer:

• NA of fiber = 0.11
• _Lambda0 = 550 nm
• Delta Lambda = 100 nm
• 5mm X 5mm CCD
• A diffraction grating

Components used to meet spec:

• Spherical Concave mirror: Thorlabs CM750-075-G01 (P.632) $73.00
  • Diameter= 25.4mm, Focal length= 75mm
• BK7 Bi-convex lens: Thorlabs LB1309 (P.572) $29.35
  • Diameter = 50.80mm, Focal Length = 75mm
• Reflecting diffraction grating: Thorlabs GR50-0605 (P.650) $169.00
  • 600 grooves/mm
• CCD Camera: Watec 902H2 Ultimate, provided by the lab
• LED Light Source: WT&T LE-01x

Mechanical mounts for optics

• Diffraction grating holder (Dimensions: 2”x 2.5”)
• Light source holder: Thorlabs LMR05 (P.146) $15.00
• Fixed lens holder: Thorlabs LMR2 (P.146) $23.00
• Retaining ring: Thorlabs SM2RR (P.146) $9.50
• Mirror holder: Newport Universal Optical Mount Model 600

Oh… I’m sleepy now. I’ll update this tomorrow.