Ultra-Stable Lasers
Supervisor
Dr Randy Bartels
Team MembersSteven Dorlac, Andrew Wiersma, Daxsamuel Chitechi, Derrick Bernallie
Ultra-Stable Lasers
Project Overview• Develop an Optically-Based Clock– Ultra-Stable External Cavity Diode Laser (ECDL)• Stable Optical Frequency Comb
(image shown on right)
• Driving/Stabilizing Electronics– Applications
• Precision Clocks• Telecommunications• Precision Navigation Source: Encyclopedia of Laser Physics and
Technology (website)
Ultra-Stable Lasers
ECDL System Overview• Key Components
– External Cavity Diode Laser– Thermoelectric Control (TEC)– Power Supply (PSU)– Piezo-Electric Power Supply
(PZT PS)– Diode Driver– Loop Control/Filter– Optics
PSUTEC
ControlOptics
ECDL
Stable Light
PZT PS
Current Controller
Ultra-Stable Lasers
Semester Goals and Assignments• Develop ECDL electronics– Diode Driver: Andy Wiersma
– TEC: Dax Chitechi
– Power Supply: Derrick Benallie
– Control/Filter: Steven Dorlac
Current Controller
PSUTEC
ControlOptics
ECDL
Stable Light
PZT PS
Current Controller
• Supplies a very low noise current to the LASER diode
• Typical Inputs– Power Supply
• Supplies power to the Current Driver to produce a current
– Servo Circuit• Provides feedback to the Current
Driver to compensate for changes
• Typical Outputs– Laser Diode
• Supplies Current to the Diode
Current Controller Overview
Current Controller Key Parts
1) Supply Source
2) Circuit Feedback
3) Current Line4) Output to
Diode
Thermoelectric Controller
PSU Current Controller
ControlOptics
ECDL
Stable Light
PZT PS
TEC
• Maintain the ECDL at constant temperature.
• Typical inputs:– Thermistor &
thermocouple
• Typical outputs:– Peltier cooler & heater
Thermoelectric controller overview
Thermoelectic Controller Key Parts
1) Low power low cost 2.5V reference
2) Gain stage3) Peltier
cooling and heating stage
Power Supply
PZT PS
TEC
ControlOptics
ECDL
Stable Light
Current Controller
PSU
• Supplies Power other Circuits – General power
• TEC• PZT PS• Current Controller
• Cost effective to simply purchase
Pulsed Power Supply
PSUTEC
ControlOptics
ECDL
Stable Light
Current Controller
PZT PS
• Supplies Power to the PZT Driver – Provides high voltage supply
to supply to PZT
• Piezoelectric Disc– Mounted to back of optical
mirrors– Changes Cavity Length
• Changes output freqency
Pulsed Power Supply
Pulsed Power Supply
• More efficient • Carefully designed not
to have high power peaks
Control/Filter Electronics
PSUTEC Current Controller
Optics
ECDL
Stable Light
PZT PS
Control
• Stabilizes ECDL Frequency• Can be cascaded• Typical Inputs
– Photodetector
• Typical Outputs– Piezo Disc
• Adjusts External Cavity
– Diode Driver• Adjusts Current to Diode
Control/Filter Electronics
Key Components
Input Monitor
PI
Mode Selection
Signal In
Control Out
Budget1) Current Controller Parts: $138.432) Thermoelectric Cooling Parts: $76.153) Power Supply Parts: $133.774) Loop Electronics Parts: $109.31-Total for parts so far:$457.67 -Amount coming in from senior design: $350-We plan on getting the rest of our funding from Prof. Bartels for the PCB and any extra costs we come across -PCB: ~$50 for each circuit= $200-One major expense we still have other than the PCB is two EMCO model G03 which we are currently looking for more affordable alternative replacement parts
Review
• ECDL Circuits– Connections– Purpose– Features
PSUTEC
ControlOptics
ECDL
Stable Light
PZT PS
Current Controller
Next Semester Plans/Goals
• Design, Integrate and Build ECDL components– Diode Housing, External Cavity, Mirrors, Gratings, Piezo Discs,
Photodetector
• Assemble ECDL system– Attach electronics– Setup and calibration of electronics
• Achieve stable optical comb output from ECDL
Thanks for Listening
Any Questions?
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