University of Pavia · B.Sc. in Physics · A.Y. 2022–23
Giovanni Nicola D'Aloisio
Experimental optics course covering LED/photodiode characterisation, laser diffraction, polarisation, optical activity, and light absorption.
All analysis notebooks are written in Python (Jupyter/Colab); raw data acquired with oscilloscopes and spectrometers and stored as CSV/XLSX.
physics-optics-lab-3/
├── 01_LED_photodiode_DC/ ← I-V characteristic & DC coupling LED→PD
│ └── data/{part1, part2}/ ← Multimeter CSV at varying load resistances
├── 02_LED_photodiode_reverse/ ← Reverse-biased photodiode I-V
├── 03_LED_photodiode_AC/ ← Frequency response, bandwidth measurement
├── 04_LED_spectroscopy/ ← LED electro-optical characterisation:
│ └── data/ electric spectrum, optical spectrum, key parameters
│ ├── LED_ELECTRIC_SPECTRUM.CSV
│ ├── LED_OPTIC_SPECTRUM.CSV
│ └── LED_PARAMETERS.CSV
├── 05_lens_collimation_focusing/ ← Thin-lens equation, collimation of LED source
│ └── data/ ← 3 collimation configs + no-lens reference + p-q pairs
├── 06_light_absorption/ ← Beer-Lambert law: 4 LED wavelengths × 3 filter colours
│ └── data/{LED_BLUE,GREEN,RED,YELLOW}/
├── 07_laser_diffraction/ ← Single & double slit diffraction
│ ├── data/ with red and green lasers; slit width inversion
│ │ ├── Diffraction.xlsx
│ │ └── LaserDiffraction.xlsx
│ ├── Notes.pdf ← Handwritten derivation notes
│ └── images/ ← Diffraction pattern photos (JPG)
│ ├── Green/{Single, Double_A, Double_B}/ ← 5+4+3 images
│ └── Red/{Single, Double_A, Double_B}/ ← 5+4+3 images
├── 08_malus_law_and_wave_plates/ ← Malus's law + λ/4 and λ/2 wave-plate characterisation
├── 09_optical_activity/ ← Optical rotation in sugar solutions, Biot's law
└── 10_cosmic_rays/ ← Bonus: Geiger counter coincidence measurement
└── data/RawData.CSV
Single and double-slit diffraction patterns were photographed and quantitatively analysed for two laser wavelengths:
| Laser | λ | Slit configs | Images |
|---|---|---|---|
| Green diode | 532 nm | Single (5 widths) + Double A (4 spacings) + Double B (3 spacings) | 12 JPG |
| Red diode | 650 nm | Single (5 widths) + Double A (4 spacings) + Double B (3 spacings) | 12 JPG |
The notebook Diffrazione da fenditura singola e doppia.ipynb implements:
- Fraunhofer single-slit envelope fitting → slit width inversion
- Double-slit interference fringe spacing → slit separation
- Cross-validation between electric and optical measurements
| # | Experiment | Key physics | Instruments |
|---|---|---|---|
| 01 | LED-PD DC coupling | I-V curve, load line | Multimeter, variable R |
| 02 | Reverse-biased PD | Dark current, breakdown | Picoammeter |
| 03 | PD frequency response | Bandwidth, RC time constant | Function generator, oscilloscope |
| 04 | LED spectroscopy | Bandgap, EL spectrum, optical spectrum | Spectrometer |
| 05 | Lens collimation | Thin-lens equation, f-number | Optical bench, CCD |
| 06 | Light absorption | Beer-Lambert law, extinction coefficient | Photodiode, filters |
| 07 | Laser diffraction | Fraunhofer diffraction, slit inversion | Laser, slits, CCD |
| 08 | Malus's law + wave plates | Polarisation, birefringence | Polarisers, wave plates |
| 09 | Optical activity | Faraday rotation, Biot's law | Sugar solutions, polarimeter |
| 10 | Cosmic rays | Coincidence counting, Poisson statistics | Geiger-Müller tubes |
pip install numpy scipy matplotlib pandas openpyxl
jupyter notebookOr open in Google Colab.
CC BY-NC-ND 4.0 · © 2023 Giovanni Nicola D'Aloisio