THORLABS LLD1530 User manual

LLD1530
Frequency-Locked Laser
User Guide

Frequency-Locked Laser
Table of Contents
Chapter 1Warning Symbol Definitions..............................................................................................1
Chapter 2Safety....................................................................................................................................2
Chapter 3Specifications......................................................................................................................3
3.1.Specification Tables........................................................................................................3
3.2.Graphs..............................................................................................................................5
Chapter 4Controls and User Interface...............................................................................................7
4.1.Front Panel Features....................................................................................................... 7
4.2.Back Panel Features .......................................................................................................8
4.3.Digital I/O..........................................................................................................................9
Chapter 5Operation.............................................................................................................................10
5.1.Description.....................................................................................................................10
5.2.Start-Up Procedure .......................................................................................................11
5.3.Automatic and Manual Modes of Operation ............................................................... 11
5.4.Disabling the Laser .......................................................................................................12
5.5.Warm Up and Stability ..................................................................................................12
5.6.Laser Safety Interlock ...................................................................................................12
Chapter 6General remarks.................................................................................................................13
6.1.Use of the Equipment ...................................................................................................13
6.2.Maintenance and Repair ............................................................................................... 13
Chapter 7Mechanical Drawing...........................................................................................................14
Chapter 8Troubleshooting.................................................................................................................15
Chapter 9Regulatory...........................................................................................................................16
Chapter 10Declaration of Conformity.................................................................................................17
Chapter 11Thorlabs Worldwide Contacts..........................................................................................18

Frequency-Locked Laser Chapter 1: Warning Symbol Definitions
Rev A, March 23, 2018 Page 1
Chapter 1 Warning Symbol Definitions
Below is a list of warning symbols you may encounter in this manual or on your device.
Symbol Description
Direct Current
Alternating Current
Both Direct and Alternating Current
Earth Ground Terminal
Protective Conductor Terminal
Frame or Chassis Terminal
Equipotentiality
On (Supply)
Off (Supply)
In Position of a Bi-Stable Push Control
Out Position of a Bi-Stable Push Control
Caution: Risk of Electric Shock
Caution: Hot Surface
Caution: Risk of Danger
Warning: Laser Radiation
Caution: Spinning Blades May Cause Harm

Frequency-Locked Laser Chapter 2: Safety
Page 2 STN050884-D02
Chapter 2 Safety
WARNING
Wavelength ~1.53 µm
Maximum Output Power < 10 mW
Beam Divergence ~ 0.2 rad
The classification of this laser follows the European Standard IEC 60825-1:2014.
Viewing the laser output with telescopic optical instruments (for example, telescopes and binoculars) close to
the aperture may pose an eye hazard! Using the instrument in combination with collimating optics may have
an impact on the assigned laser classification. The safety of any system incorporating the equipment is the
responsibility of the assembler of the system.
Use of controls or adjustments or performance of procedures other than those specified herein may result in
hazardous radiation exposure. There are no user-serviceable parts inside the instrument – never remove the
red cover from the instrument.
WARNING
Do not open the instrument. Risk of electric shock. Please use the instrument only in combination with the
included power chord and make sure that a connection to earth ground is given.
WARNING
If the equipment is used in a manner not specified by the manufacturer,
the protection provided by the equipment may be impaired. Do not load the top of the instrument with weight.
The instrument contains less than 10 ml of C2H2at a pressure of 2 Torr.
WARNING
Do not cover the fan grill on the back of the instrument.
CAUTION
This instrument should be kept clear of environments where liquid spills or condensing moisture are likely.
The LLD1530 frequency-locked laser is not water resistant. To avoid damage to the instrument, do not
expose it to spray, liquids, or solvents.

Frequency-Locked Laser Chapter 3: Specifications
Rev A, March 23, 2018 Page 3
Chapter 3 Specifications
3.1. Specification Tables
Performance Specifications
Parameter Min Typ. Max Unit Notes
Center Vacuum Wavelength 1532.8323 nm
Stability (Long Term)
- < ±10 ±25 MHz
After Warm Up1
- < ±0.08 ±0.2 pm
- < ±0.00033 ±0.00085 cm-1
Accuracy (at Start Up)
- < ±15 ±25 MHz
- < ±0.12 ±0.2 pm
- < ±0.00050 ±0.00085 cm-1
Precision (at StartUp)
- < 1 -- MHz
After Warm Up and for
Constant Environmental
Conditions
- < 0.008 - pm
- < 0.00003 - cm-1
Laser Linewidth (FWHM) - <3 - MHz
Found by measuring the
beat note between two
locked LLD1530 lasers
over a 10 µs duration.
Side Mode Suppression
Ratio (SMSR) 35 - - dB
Relative Intensity Noise
(RIN) - 100 - dBc/Hz
20 MHz Measurement
Bandwidth, 200 ms
Signal Acquisition
Optical Power Stability - 1.1 - % 30 minute Duration
Optical Output Power - - 10 mW IEC 60825-1:2014
Max Change in Ambient
Temperature before
Frequency Re-Lock
Needed2
T = ±3.5 °C
Ambient Temperature
Change Triggering
Frequency Re-Lock3
T = ±(0.9)*3.5 °CAUTO Mode Only
Laser Class4Class 1
Optical Fiber Type SMF-28 Ultra
1Variations in the instrument’s temperature are the main source of wavelength drift. Maintaining operation within specifications requires re-
locking the laser wavelength after a temperature change of 3.5 °C. Re-locking events are triggered automatically when operating in AUTO
mode, and an LED on the front panel indicates the need to re-lock when operating in MANUAL mode.
2When operating in MANUAL Mode, the LOCKED staus LED will be extinguished when the temperature change exceeds these limits. The
performance specifications given above will not apply if the LOCKED status LED is not illuminated. When operating in AUTO mode, the
instrument's frequency will be automatically re-locked before these limits are reached.
3In MANUAL mode, the RELOCK NEEDED status LED illuminates when these limits are exceeded. If the RELOCK NEEDED status LED is
illuminated, the performance specification given above will not apply. In AUTO mode, external disturbances that cause loss of frequency
locking also trigger a re-lock procedure.
4Collimation optics are not recommended for use with this laser, as their use may result in the emission limit for Class 1 laser products being
exceeded.

Frequency-Locked Laser Chapter 3: Specifications
Page 4 STN050884-D02
Connectors
Parameter Value
Optical Fiber Connector FC/APC
Digital control interface D-Sub 9 pin Female
Environmental and Power Specifications
Parameter Value
Operating Temperature Range510 °C - 40 °C
Storage Temperature Range 0 °C - 60 °C
Power requirements 100 - 240 VAC, 0.3 A, 50 - 60 Hz
Fuse 0.5 A, 250 V, Type T, 5 x 20 mm
Maximum Operating Altitude 2000 m Above Sea Level
5Non Condensing

Frequency-Locked Laser Chapter 3: Specifications
Rev A, March 23, 2018 Page 5
3.2. Graphs
Figure 1 The top plot shows the typical variation in the LLD1530's vacuum emission wavelength
over one hour. Frequency stability data were measured using two LLD1530 lasers and a beat note
approach; one LLD1530 was intentionally operated with a slightly detuned optical frequency to
generate the beat note. The frequency measurements were converted to wavelength for the plot.
The data in the bottom plot were measured using Thorlabs' OSA205C and show the typical long-
term vacuum wavelength stability of the LLD1530. All data were acquired while the lasers
operated in MANUAL Mode under ambient conditions. No re-locking procedures were performed
during data acquisition.

Frequency-Locked Laser Chapter 3: Specifications
Page 6 STN050884-D02
Figure 2 Plot showing a typical side mode suppression ratio (SMSR) of the DFB laser integrated
into the LLD1530 laser reference system.
Figure 3 Typical beat note spectrum between two LLD1530 frequency-locked laser sources (blue
curve), plotted with a Lorentzian curve fit (red curve). The beat note was recorded over 10 µs
using a 150 MHz detector. A 2.5 MHz FWHM linewidth was derived from the measurement data and
the 3.6 MHz FWHM of the curve fit.

Frequency-Locked Laser Chapter 4: Controls and User Interface
Rev A, March 23, 2018 Page 7
Chapter 4 Controls and User Interface
The front and back panels of the instrument include instrument status indicators, controls, optical output ports and
a digital I/O interface. The locations and functionality of these features are described in the following.
WARNING
Caution – Use of controls or adjustments or performance of procedures other than
those specified within this manual may result in hazardous radiation exposure!
4.1. Front Panel Features
Label Function
F1 LED Indicates Power is Supplied to Unit
F2 LED Indicates Laser Frequency is Locked within ±25 MHz Range
F3 LED Indicates Laser Frequency is Near the Edge of the ±25 MHz Range
F4 Button to Trigger Laser Re-Lock Procedure
(Enabled in Manual Mode Only)
F5 Key Switch Provides Power to the Unit
F6 LED Indicates Operation in Automatic Mode
F7 LED Indicates Operation in Manal Mode
F8 Button to Switch between Automatic and Manual Modes
F9 Laser Emission Output Aperture, FC/APC Connector
F10 Button to Enable Laser Emission
F11 LED Indicating Laser is On and Laser Emission Present
F1
F2
F3
F4
F5
F6
F7 F8
F9
F11
F10
INVISIBLE LASER
RADIATION EMITTED
FROM THIS APERTURE

Frequency-Locked Laser Chapter 4: Controls and User Interface
Page 8 STN050884-D02
4.2. Back Panel Features
Label Function
B1 Laser Interlock Jack
B2 Digital I/O Interface, Female DB9 Connector
B3 AC Power Cord Connector
B1
B2
B3