Public Lab Research note


The user 'dhaffnersr' has been placed in moderation and will not be able to respond to comments.

Laser Calibration (532nm) of New DVD Diffration Grating 4.7 GB

by dhaffnersr | September 12, 2016 16:47 | 93 views | 1 comments | #13443 | 93 views | 1 comments | #13443 12 Sep 16:47

Read more: stable.publiclab.org/n/13443


Resolution and Calibration for the DH 4 v4a Spectrometer

I replaced the DVD diffraction grating for my spectrometer in order to get a more balanced spectral resolution that the JDEPC-OV05 cmos camera can easily process @ its pixel specifications, also I believe with further testing, it will help, since I cannot control exposure time, only gamma correction with Spekwin32.

The new ruling density for the diffraction grating is now; 4.7 GB = 0.74mm @ 1540 lines with a wavelength range of 650nm.

My Aries 532nm Green portable laser was used to calibrate the spectral bandwidth data table is given below;

Data_for_laser_calibration_sept_12.png

Figure.1 is the laser line at FWHM, shown on the plot with the horizontal green line at exactly 0.37323[nm]

532nm_laser_in_ISO_sept12_test02.png

Figure.2 is the laser peak at 531.39nm (laser allowed to warm up for 1 minute), just shy of the 531.65 central wavelength for this laser specified on it's specifications sheet.

532nm_laser_in_ISO_sept12_test02_PEAK.png

Figure.1a is the CFL calibration I did today using Plab spectral workbench 2, you can see from the title picture, that there is clearly 2 distinct green lines and a clear second blue line, I marked all the lines just for reference purposes.

CFL_calibration_title_pic_sept_12.png

Figure.2 is a zoomed in view of the second blue spectral line

CFL_cal_fit_of_7_sept_12_blue_peak.png

Figure.3 is a zoomed in view of the double green peaks

CFL_cal_fit_of_7_sept_12_grn_peak.png

Figure.3a is the full plot for the CFL spectrum with a quality "fit" of 7 using the 4.7 GB DVD diffraction grating

CFL_cal_fit_of_7_sept_12.png


1 Comments

Correction for the data table, R = 531.39/569.8 = 0.93, NOT 1.11

Data_for_laser_calibration_sept_12.png

Reply to this comment...


Login to comment.