Vorsprung durch InnovationLB2001 & LB2005

Servo Controller

Electronic Systems & Devices

Pound Drever Hall Locking Scheme- High Speed Servo Controller - Modulator Demodulator

LOCKING SCHEMES

Side Of FringeTop Of FringePound Drever HallBjorklund

MOT & REFERENCE CELLS

Rubidium Cesium

Potassium Lithium

Optical Cooling & TrappingUltrastable Laser Systems

0.05

0.10

0.15

0.20

0.25

-500 -400 -300 -200 -100 0 1000.09

0.10

0.11

0.12

Bala

nce

d S

ignal [

mV

]

156.95 MHz 266.65 MHz

F=3

F=2 co 3

F=1 co 3

F=2

F=1 co 2

Lase

r T

ransm

issi

on [ m

V ]

Frequency [ MHz ]

87Rb : 5S

1/2, F=2 - 5P

3/2 F=

F=1

-0.1

0.2

0.3

0.4

0 2 4 60.04

0.06

0.08

0.10

0.12

0.14

87RB: 5S

1/2, F=1 - 5P

3/2, F=0,1,2

85RB: 5S

1/2, F=2 - 5P

3/2, F=1,2,3

85RB: 5S

1/2, F=3 - 5P

3/2, F=2,3,4

Bala

nce

d S

ignal [

mV

]

6.834 GHz

87RB: 5S

1/2, F=2 - 5P

3/2, F=1,2,3

3.035 GHz

Lase

r Tra

nsm

issi

on [ m

V ]

86420-4-6-820

30

40

50

60

70

8050-5

-50

0

50

200

La

ser

tra

nsm

issi

on

[ m

V ]

5.170 G Hz 4.021 G H z

62P

1/2,F=3 - 6

2P

3/2,F=[3 ,4 ,5 ]

Ba

lan

ced

sig

na

l [ m

V ] 6

2P

1/2,F=4 - 6

2P

3/2,F= [2 ,3 ,4 ]

-400 -200 0 200 400

0.03

0.04

0.05

0.06

0.07

-400 -200 0 200 400

0.10

0.15

0.20

0.25

La

ser

tra

nsm

issi

on

[ m

V ]

Re lative Frequency [ M Hz ]

F= 3

F= 4 co 5

F= 4

F= 3 co 4

F= 3 co 5

F= 3

133C s-D 2 : 6

2P

1/2,F=4 - 6

2P

3/2,F=

Ba

lan

ced

sig

na

l [ m

V ]

133D2 Transitions in Rb, central wavelength 780.27nm D2 - Transitions in Cs, central wavelength 852.347 nm

0

50

62P

1/2,F=3 - 6

2P

3/2,F=[3 ,4 ,5 ]

an

ce

dsi

gn

al[m

V

6 P1/2

,F 4 6 P3/2

,F [2 ,3 ,4 ] 200

V]

62P F=4 - 6

2P F=[2 3 4]

0.2

0.3

ance

d S

ignal [

m 3.035 GHz

0.4

mV

]

6.8334 GHz

Scientific Lasers

Side of Fringe Type of Lock

Application Examples

Several types of laser stabilization schemes are known in literature. We summarized some of the most common types of locking schemes as block diagram.The oscilloscope screen shot shows a typical view of the specroscopy, before

Pound Drever Hall Type of Lock

Bjorklund Type of Lock

Rubidium D2 Line

Rubidium D2 Line

Rubidium D2 Line

Saturated Rb Spectrum

Red Curve:Saturated Rb Spectrum

Green Curve:Phase Modulated Spectrum

Red Curve:Saturated Rb Spectrum

Green Curve:RF Modulated Spectrum

applying the lock.

Product Features

Modulator Demodulator (Pound Drever Hall)

Modulation Frequency 1kHz .. 100MHz

Phase Delay 0° .. 360°

Modulation Amplitude up to 0dBm

Modulation Amplitude up to 20dBm (optional)

Input Impedance 50W (Photodetector)

Output Impedance 50W (RF Modulation)

Output Impedance 50W (Error Signal)

Frequency Generation 2 x DDS

Internal Data

Processor 300MHz FPGA

System Clock 3GHz

System Bandwidth up to 100MHz

Common Data (General)

Dimension (WxHxD) 270 x 110 x 320 mm

Weight < 5kg

Line Voltage 115V / 230V +/- 10%

Line Frequency 50 .. 60Hz

Warm-up Time 10min

Storage Conditions -25 .. 70°C

Operating Temperature 0 .. 40°C

Servo Controller (Lockbox)

PI Corner Frequency (high) 1Hz .. 1MHz (HF Path)

PI Corner Frequency (low) 1 Hz .. 100kHz (LF Path)

Amplification -40dB .. +40dB

Input Impedance 1MW

Output Impedance (high) 50W

Output Impedance (low) 1MW

Low Frequency Limit

Integration Hold Mode

Internal Data

Processor 300MHz FPGA

D/A Converters sleeping mode

System Bandwidth 10MHz

Interface USB

Remote Control Software Package

Flexibility

Stand-Alone Unit

Laser Manufacturer independent

Common Data (Remote Control)

High speed FPGA controlled proportional integral (PI)

servo controller for external cavity diode laser systems

as well as DFB diode lasers. Model LB2001 allows to

stabilize the laser frequency via piezo- and laser current

feedback path.

High frequency Modulator/Demodulator for Pound

Drever Hall type of lock. Model Lb2005 is prepared for

ooperation with the Servo Controller LB2001 for

generating a Top of Line type of lock.

Both Models enable an easy, intuitive and highly stable

Top of Line type of lock.

Specifications

The graph shows the effect of applying the high bandwidth type of lock to the noise figure of the laser system. The red curve show the noise figure of a free running DFB laser. The green curve shows the noise figure of the locked DFB laser. This significant reduction of the RIN noise results into a linewidth narrowing of the laser.

Sacher Lasertechnik is leading manufacturer of tunable external cavity diode lasers (ECDLs) with more than 20 years of experience. The product range includes anti-reflection coated diode lasers, ECDLs in Littrow and in Littman/Metcalf configuration as well as driver electronics for the LD and sophisticated measuring electronics.Please contact us with your measurement requirements. We would be proud to support you with our competence.

Noise Reduction and Linewidth Narrowing

Application Example

Company Profile

About Sacher Lasertechnik

Please contact us

Sacher Lasertechnik

R. Breitscheid Str. 1-5D-35037 Marburg/Lahn

Tel.: +49 6421 305 - 0Fax: +49 6421 305299

Sacher Lasertechnik

5765 Equador WayBuena Park, CA90620

Tel.: 1-800-352-3639Fax: 1-714-670-7662

GmbH

Germany

LLC

U. S. A.

Email: contact@sacher.de Web: http://www.sacher.de

1k 10k 100k

-105

-100

-95

-90

-85

-80

-75

-70

-65

-60

-55

Comparison of noise spectra for 780nm DFB diodelaser

No

ise

Sp

ect

ra[d

BV]

Frequency [Hz]

free running locked

Sacher Lasertechnik Group