Difference between revisions of "Kerr - June 1, 2016"
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(Created page with "Here is an outline to get started...let's evolve as project proceeds... Part I – Become familiar with polarized light and optical measurements Basic Setup 1. Find low powe...") |
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| − | Here is an outline to get started...let's evolve as project proceeds... | + | Here is an outline to get started...let's evolve as project proceeds...[[media:160601_Kerr_Outline.docx]] |
| − | Part I – Become familiar with polarized light and optical measurements | + | === Part I – Become familiar with polarized light and optical measurements === |
| − | Basic Setup | + | ;Basic Setup |
| − | + | * Find low power (<20 mW) laser and parts needed to do this: | |
| − | + | * Send light to power meter to get familiar with power level and control | |
| − | + | * Add a polarizer to define plane of polarization | |
| − | + | * Add an analyzer to find maximum and minimum e.g. “Law of Malus” | |
| − | + | * Between cross polarizers vary angle of half- and quarter- wave plates | |
| − | + | * Compare the different configurations to Thorlabs optical polarimeter | |
| − | Photodiode and Scope Setup | + | ;Photodiode and Scope Setup |
| − | + | * Find a photodiode and scope to see intensity signal in real time | |
| − | + | * Define polarization and analyzing planes of crossed polarizers | |
| − | + | * Convince yourself that intervening half-wave plate can leak light | |
| − | + | * Insert Hinds AOM and demonstrate it works as a fast wave plate | |
| − | + | * Use lock-in amplifier to extract the AOM amplitude using photodiode | |
| − | + | * Compare the configuration to the Thorlabs optical polarimeter | |
| − | Part II – Test Kerr signal using a magnetized foil | + | === Part II – Test Kerr signal using a magnetized foil === |
| − | Basic Setup – Analyze linear polarization angle from iron foil | + | ;Basic Setup – Analyze linear polarization angle from iron foil |
| − | + | * Find iron foils, pucks and permanent magnets | |
| − | + | * Reflect laser off un-magnetized iron foil between cross-polarizers | |
| − | + | * Use (variable) waveplate to test sensitivity to linear polarization plane | |
| − | + | * Test signal as permanent magnets are added (measure field) to foil | |
| − | + | * Move magnets relative to foil, test sensitivity | |
| − | + | * Learn how to demagnetize the foil | |
| − | Advanced Setup – Photodiode and Scope Setup | + | ;Advanced Setup – Photodiode and Scope Setup |
| − | + | * Try Thorlabs polarimeter or fast photodiode to measure signal | |
| − | + | * Repeat basic setup using the Hinds modulator; vary the foil magnetization | |
| − | + | * Evolve sophistication of setup to best resolve plane of polarization | |
| − | Part III – Kerr measurements of magnetized puck | + | === Part III – Kerr measurements of magnetized puck === |
| − | Setup – Integrate your diagnostic at Magnet Measurement Facility (MMF) | + | ;Setup – Integrate your diagnostic at Magnet Measurement Facility (MMF) |
| − | + | * Become familiar with the new magnet coil geometry, field | |
| − | + | * Devise a means to add your foil and with geometry like that of photogun | |
| − | + | * Move or re-build your Kerr diagnostic at the MMF | |
| − | Experiment | + | ;Experiment |
| − | + | * Measure plane of polarization vs. power supply current (magnetic field) | |
| − | + | * With MMF help measure magnetic field at face of iron | |
Latest revision as of 12:02, 1 June 2016
Here is an outline to get started...let's evolve as project proceeds...media:160601_Kerr_Outline.docx
Part I – Become familiar with polarized light and optical measurements
- Basic Setup
- Find low power (<20 mW) laser and parts needed to do this:
- Send light to power meter to get familiar with power level and control
- Add a polarizer to define plane of polarization
- Add an analyzer to find maximum and minimum e.g. “Law of Malus”
- Between cross polarizers vary angle of half- and quarter- wave plates
- Compare the different configurations to Thorlabs optical polarimeter
- Photodiode and Scope Setup
- Find a photodiode and scope to see intensity signal in real time
- Define polarization and analyzing planes of crossed polarizers
- Convince yourself that intervening half-wave plate can leak light
- Insert Hinds AOM and demonstrate it works as a fast wave plate
- Use lock-in amplifier to extract the AOM amplitude using photodiode
- Compare the configuration to the Thorlabs optical polarimeter
Part II – Test Kerr signal using a magnetized foil
- Basic Setup – Analyze linear polarization angle from iron foil
- Find iron foils, pucks and permanent magnets
- Reflect laser off un-magnetized iron foil between cross-polarizers
- Use (variable) waveplate to test sensitivity to linear polarization plane
- Test signal as permanent magnets are added (measure field) to foil
- Move magnets relative to foil, test sensitivity
- Learn how to demagnetize the foil
- Advanced Setup – Photodiode and Scope Setup
- Try Thorlabs polarimeter or fast photodiode to measure signal
- Repeat basic setup using the Hinds modulator; vary the foil magnetization
- Evolve sophistication of setup to best resolve plane of polarization
Part III – Kerr measurements of magnetized puck
- Setup – Integrate your diagnostic at Magnet Measurement Facility (MMF)
- Become familiar with the new magnet coil geometry, field
- Devise a means to add your foil and with geometry like that of photogun
- Move or re-build your Kerr diagnostic at the MMF
- Experiment
- Measure plane of polarization vs. power supply current (magnetic field)
- With MMF help measure magnetic field at face of iron