Available Photonics Experiments:

P5838 Detection of light PDF Download page

  • White light lamp
  • Prism refractometer
  • Black body radiation
  • Si, InGaAs photodetector
  • Thermoelectric Detector
  • Photometer
  • Characterization of photodetectors
  • Characterization of filter
  • Examples of investigations and measurements
OX General setup
A tunable light source consisting of the white light tungsten lamp (7) and the prism tuner (13). The light from the tungsten lamp is guided by means of a glass fibre bundle (12) with circular to rectangular cross section transformer (12). A prism tuner has been chosen because no ghost images due to higher order of a grating spectrometer exist for prism. Using a grating tuner would require a set of high order blocking filters which makes the setup complex and unhandy.
The advantage of the special prism arrangement lies also in the fact that the optical axis is the same for the entrance and exit for all wavelength. The tuning is of the wavelength is done by turning the micrometer screw and using the provided linear calibration curve. For the measurement of the intensity of the particular wavelength a wavelength independent sensor (15) is used
OX Characterization of optical filter
The emission leaving the prism tuner is shaped by a set of cylindrical lenses (14) in such a way that almost the entire radiation reaches the photodetector. The final focussing is done by the lens (2).
By placing an optical filter (1, 3) into the beam path the spectral transmission curve can be recorded. For this purpose the wavelength is tuned in useful steps and the transmitted intensity is measured. The plot of the intensity versus the wavelength is the spectral transmission of the particular filter.
During the measurement series the filter is removed for each wavelength to obtain the spectral intensity distribution curve of the tungsten lamp. Using this information the normalised filter curve is obtained.
OX Spectral and temporal properties of photodetectors
To measure the spectral sensitivity of a photodetector it is simply plugged into the setup instead of the power sensor (16). Two types of detectors are provided, one for the visible (5) and one for the near infrared part of the spectrum. The particular detector is connected to the signal conditioning box (4) which out put can be connected to a digital voltmeter but preferable to an oscilloscope. In conjunction with the light chopper high sensitive AC measurements can be carried out. Furthermore the signal conditioning box allows the variation of the series resistor of the photodiode. This allows also to measure the temporal behaviour of photodiodes.
  • P5838 Detection of light consisting of:
14A-04641IR block filter
24B-06201Biconvex lens, f=60 mm, free opening 18 mm, click 25
34F-00041Coloured glass filter BG39, 50 x 50 x 3 mm
4ED-00601Photodetector signal conditioning box
5ED-02101PIN Photodetector, BPX61 with connection leads
6ED-02201Photodetector, InGaAs with connection leads
7LS-02101White light source 150W
8MC-00081Profile rail MG-65, 800 mm
9XM-00701Module F - Filter plate holder
10XM-08041Light chopper on carrier, controller
11XM-10902Mounting plate C25 with carrier 20 mm
12XM-21101Imaging optics with fibre bundle
13XM-21201Tunable wavelength selector
14XM-21302Imaging cylindrical optics
 Required Options:  
 TP-00421Laser power meter LabMax-TO
 TP-00461 High sensitive power sensor, 0.3-11 µm
 TP-01001Oscilloscope 100 MHz digital, two channel