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?