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Sacher Lasertechnik

Next Generation Littrow

LYNXTM Joachim R. Sacher

(confidential technical documentation)

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Littrow Laser Products

Application Optical Cooling & Trapping Raman Spectroscopy Holography

Award Winning Product CLEO Conference 2000

Cavity Layout

Product Photo


Next Generation Littrow Cavity

LaserEmission

WavelengthAdjustment

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Littrow Laser Products – Industrial Grade

Excellent Stability Low Temperature

Drift >3kHz Cavity

Resonace Freq. Narrow Linewidth

<100kHz


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Performance Data @ 780nm 780nm

767nm Temperature Behavior

795nm


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Temperature Cycling

Excellent wavelength stability over >24 hours temperature cycling

No laser stabilization during measurement

Simple compensation via Locking electronics


Operation Performance On – Off Repeatability

Excellent repeatability after start-up sequences.

Back to the absorption line within a few minutes after restarting laser current,

no loss of the absorption line

0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5793,4010

793,4015

793,4020

793,4025

793,4030

793,4035

793,4040

793,4045

793,4050

Wav

elen

gth

/ nm

Time / hours0 5 10 15 20 25 30

780,024

780,025

780,026

780,027

780,028

22,6

22,8

23,0

23,2

23,4

Tem

pera

ture

(B

asep

late

) / °

C

Wav

elen

gth

/Vac

uum

) / n

m

Time / hours

Full StartupTemp & Current

Partial StartupLaser Current

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Tuning Concepts Mode-Hop Free Tuning

Grating

Grating

Grating

(a)

(c)

(b)

Pivot Point

Grating

Laser

True Pivot Point Selection

Exact Choice of x0, x1, x2

Synchronization Cavity Defined Wavelength Grating Defined Wavelength

Result: Mode-Hop Free Tuning


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Tuning Concepts

Ricci & Hänsch Littrow Cavity Concept *

* L. Ricci, M. Weidemüller, T. Esslinger, A. Hemmerich, C. Zimmermann, V. Vuletic, W. König, T.W. Hänsch, A compact grating-stabilized diode laser system for atomic physics, Optics Communications 117, page 541-549, June 1995

Littrow Cavity Compromise Favoring High Frequency Cavity

Resonances over Mode-Hop Free Tuning

Result: Virtual Pivot Point Concept

Problem Insufficient Cavity Length Variation

during Piezo Scan of Cavity Gratingdue to Virtual Pivot Point Concept

Solution Enhancement of Mode-Hop Free via

Synchronious Piezo – Laser CurrentModulation

Change of Laser Current changesthe Optical Path Length of Laser Diode due to Electro-Optic Effect

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Tuning Concepts Virtual Pivot Point

Virtual Pivot Point 2

Synchronization Cavity Defined Wavelength Grating Defined Wavelength Laser Current with Piezo Voltage

Result: Enhanced Mode-Hop Free Tuning

Grating

Laser

Pivot Point 1

Rotation

Pivot Point 2

Tuning Results Piezo Fine Scan

Rubidium Absorption

Result: Full Mode-Hop Free Tuning Limited by Piezo Actuator

0 500 1000 1500 2000

780,908

780,910

780,912

780,914

780,916

780,918

780,920

780,922

780,924

780,926

Wav

elen

gth

[nm

]

Time [s]


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Linewidth Measurement

Measurement Setup Hetherodyne Beat Setup Laser 1: Littrow Cavity Laser 2: Littrow Cavity

Test Results Hetherodyne Beat Setup Linewidth: <<100kHz

< 15kHz (typ.)

Scan Rate: 1ms / div. RBW: 100kHz

499,0 499,2 499,4 499,6 499,8 500,0 500,2 500,4 500,6 500,8 501,0

70

140

210

Inte

nsity

/ dB

Frequency / MHz

499,0 499,2 499,4 499,60

1x1021

2x1021

Data: Data4_DModel: LorentzEquation: y = y0 + (2*A/PI)*(w/(4*(x-xc)^2 + w^2))Weighting: y No weighting Chi 2/DoF = 1.5411E40R^2 = 0.88367 y0 -2.0046E19 ±1.1603E19xc 499.32448 ±0.0004w 0.01921 ±0.00119A 6.6969E19 ±3.0936E18

2x Littrow, Linear Scale, FWHM = 10 KHz

Frequency / MHz

Inte

nsity

/ a.

u.


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Long Term Stability

Measurement Setup System locked to Rb

Reference

Test Results Long Term Stable


0 1 2 3 4 5780,220

780,225

780,230

780,235

780,240

780,245

780,250

780,255

780,260

780,265

780,270

780,275

780,280

Laser System locked to Rubidium Reference Laser Wavelength Stability

Time [h]

wav

elen

gth

[nm

]

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Realitive Intensity Noise

Measurement Setup Laser Controller (PilotPZ 500) 20MHz Photoreceiver 12 bit Digital Oscilloscope with FFT

Test Results RIN Spectrum

Laser Driver

Diode Laser

Detector

Oszi

Amplifier

0 100 200 300 400 500 600-140

-120

-100

-80

-60

-40

-20

0

Rel

ativ

e In

tens

ity N

oise

, dB

Littrow Laser S3 RIN spectrum

Frequency, Hz

0 1k 2k 3k 4k 5k-140

-120

-100

-80

-60

-40

-20

0

Rel

ativ

e In

tens

ity N

oise

, dB

Frequency, Hz

Littrow Laser S3 RIN spectrum


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Mechanic Cavity Resonance Measurment Setup

Heterodyne Beat Setup Laser 1: Littrow (not modulated) Laser 2: Littrow, 60mV Piezo Modulation Detection: Linewidth Enhancement via Modulation

Mechanic Resonances No resonances below 3kHz 1st resonance 3.4kHz 2nd resonance 4.3kHz

0 1000 2000 3000 4000 50000

5

10

15

20

25

30

35

Fre

quen

cy T

unin

g / M

Hz

Piezo Modulation Frequency / Hz


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Low Noise Laser Controllers

Micro Controller Operated Laser Controllers

Sub µA Noise Figure Up to 4000mA Laser

Current Integrated Function

Generator Integrated Piezo

Amplifier Fully Remote Control

Features USB, GPIB, RS232 Laboratory and

OEM Versions


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Technology: Micro-Controller & FPGA

Low Noise Laser Controllers

Laser Diode Current Sub µA Noise Figure

102 103 104 105

1E-12

1E-11

1E-10

1E-9

1E-8

Pilot PZ 500 Noise Spectrum

Frequency [Hz]

100mA 200mA 500mA

Cur

rent

Noi

se [A

/ H

z]10 ResistorΩ

DC Current

Electrical Spectrum AnalyzerLaser Controller


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Servo Controller

High Frequency PI Regulator 10MHz Bandwidth Adjustable Corner

Frequencies Integration Hold Function Low Frequency Gain Limit FPGA Controlled Operation Fully Remote Control

via USB

Application: Laser Stabilization Optical Cooling & Trapping

Principles of Operation

Product Photo


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Modulator & Demodulator

High Frequency Synthesizer Central 3GHz Clock 2 DDS Syntesizer 100kHz to100MHz Modulation ns Phase Adjustment High Frequency Mixer High Modulation Amplitude Fully Remote Control

via USB

Application: Laser Stabilization Pound Drever Hall Lock Optical Cooling & Trapping

Principles of Operation

Product Photo


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Application: Optical Cooling & Trapping

Laser Frequency Stabilization Frequency Tolerance <1MHz 24/7 Operation Requirement Locking to Rubidium Transition Locking to Cesium Transion Side of Fringe & Top of Line Lock

Fully Remote Control Operation Internal Operation Control via FPGA Remote Control via USB

ECDLISO PBSλ/2BS

Rb

M

MBS

Wavemeter D1 D2Lockcircuit


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Corporate Headquarter

Sacher Lasertechnik Headquarter

Space 1200m²12900 square ft.

30 employees at location


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Product Family Overview

Laser Controller Laser Controller Laser Controller

AR Coated Laser Diodes

MOPA Laser System MOPA Laser System

Littrow Laser System Littman Laser System Laser Amplifier System

DFB Laser Diodes

THz Laser System

DFB Laser Diodes

SHG Laser System

ns Pulsed Laser System

ps Mode Locked Laser

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Technology: Thin Film Coating Equipment

Thin Film Coating Equipment

Sputter Coater High Volume

Production R&D Coatings

E-Beam Coater R&D Coatings


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Technology: Diode Laser Chip Handling

Dye Bonder Laser Chip Mounting

Wire Bonder Laser Chip Electrical Connection


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Technology: Electro Optic Micro-Assembly

Multi-Emitter Fiber Coupling

Up to 12 Single Mode Emitters Fiber Coupled

Multi-Wavelength Emitter Fiber Coupled


Micro External Cavity

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Technology: Electro Optic Micro-Assembly

Compact Package Excellent Stability No Moving Parts No Mechanic Cavity

Resonances Narrow Linewidth Low Temperature

Drift


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Thank You For Your Attention!

Sacher Lasertechnik GmbHRudolf-Breitscheid-Str. 1-535037 MarburgGermany

Sacher Lasertechnik LLC.5765 Equador WayBuena Park, CA 90620United States

http://www.sacher-laser.com© 2009 Sacher Lasertechnik GmbH. All rights reserved.

sacher lasertechnik group - lynx s3 20150704docs.sacher-laser.com › lynx-s3.pdf · sacher...

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