Wavelength References Clarity Series User manual

Operators Manual
ClarityTM Precision Frequency Reference
Laser Locked to a Molecular Absorption Line
Operating Manual 0700-M Rev C
Copyright Wavelength References, 2012
All Rights Reserved
Wavelength References
1800 SW 3rd Street, #140
Corvallis, OR 97333
Voice [phone]
Fax [phone]
E-mail: [e-mail]
Wavelength References

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Warranty
Wavelength References warrants that this product will be free from defects in materials and
workmanship for a period of one (1) year from the date of shipment. If this product proves
defective during the warranty period Wavelength References, at its option, either will repair the
defective product without charge for parts and labor, or will provide a replacement in exchange
for the defective product.
In order to obtain service under this warranty Customer must notifyWavelength References of
the defect before the expiration of the warranty period and make suitable arrangements for the
performance of service. It is important that you, in advance of returning a unit, receive a Return
Material Authorization Number (RMA). This will ensure the prompt handling of the repair, as
well as provide important tracking information. Customer shall be responsible for the
packaging and shipping the defective product to the service center designated by Wavelength
References with shipping charges prepaid. Wavelength References shall pay for the return of
the product to Customer if the shipment is within the United States or Canada. Customer shall
be responsible for paying all shipping charges, duties, taxes, and any other charges for
products returned to other locations.
This warranty shall not apply to any defect, failure, or damage caused by improper use or
improper or inadequate maintenance or care.Wavelength References shall not be obligated to
furnish service under this warranty a) to repair damage resulting from attempts by other
personnel to repair or service this product; b) to repair damage resulting from improper use or
connection to incompatible equipment; or c) to service a product that has been modified.
This warranty is given byWavelength References in lieu of any other warranties, expressed or
implied. Wavelength References and its vendors disclaim any implied warranties of
merchantability or fitness for any particular use. Wavelength References’ responsibility to
repair or replace the defective product is the sole and exclusive remedy provided customers
for breach of the warranty. Wavelength References will not be liable for any indirect, special,
incidental, or consequential damages irrespective of whether Wavelength References or its
vendor has advance notice of the possibility of such damages

Table of Contents
1Introduction...................................................................................................2
1.1 Product Overview............................................................................2
1.2 Application........................................................................................2
1.3 Visual and Operational Inspection..................................................3
1.4 Options and Accessories................................................................3
1.5 Operating Environment...................................................................3
2Theory of Operation.....................................................................................4
2.1 Operating Principles........................................................................4
2.2 Accuracy..........................................................................................5
3Connections .................................................................................................6
4Operating Instructions..................................................................................7
4.1 Getting Started.................................................................................7
4.1.1 Password .....................................................................................7
4.1.2 Initial Calibration...........................................................................7
4.1.3 Interlock........................................................................................7
4.2 Front Panel Operation.....................................................................7
4.2.1 Menu ............................................................................................7
4.2.2 LOCK MODE...............................................................................9
4.2.3 CAL...............................................................................................9
4.2.4 ACTIVE........................................................................................9
4.3 Front panel display..........................................................................9
4.3.1 Frequency and Wavelength......................................................10
4.3.2 Laser Status...............................................................................10
4.3.3 Instrument Status:......................................................................10
4.4 Rear Panel.....................................................................................10
4.5 Troubleshooting.............................................................................11
5External Interface.......................................................................................12
5.1 RS232 Commands and Responses.............................................12
5.2 Error and Event Codes..................................................................14
6Specifications.............................................................................................15
6.1 Table of Specifications ..................................................................15
7Safety and Regulatory Compliance..........................................................16
8Bibliography................................................................................................16

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1Introduction
This operator’s manual contains useful information about the ClarityTM family of locked lasers. It
contains all the information you will need to operate and maintain your laser.
If you have just received your laser, refer to section 1.3 for instructions on initial inspection. For routine
operation, section 4 will be most informative.
This manual is intended to coincide with firmware version 1.00. For other firmware versions, please
consult the appropriate manual or contact Wavelength References for information.
1.1 Product Overview
The Clarity is a semiconductor laser that is locked to a molecular absorption line. Lasers can be offered
with wavelengths chosen from the spectra of acetylene, hydrogen cyanide, hydrogen fluoride, carbon
monoxide, carbon dioxide and other gases, please inquire. The standard product configurations are
available locked to a line of C12 acetylene in the 1530nm region, C13 acetylene in the 1540nm region,
and hydrogen fluoride at 1312nm. Other wavelengths can be available on special order.
The laser is available as Precision Frequency Reference (PFR) and/or a Narrowed Line Laser (NLL).
The PFR is designed to function as a primary frequency reference and offers an output that can be
used to wavelength-calibrate optical instruments. The NLL version includes PFR functionality but
additionally locks to the side of the line to provide narrowed linewidth capability.
The locking process is fully automatic and extremely robust. The fully digital architecture also allows for
correction of many errors that could creep into a design based on older analog techniques.
This locking process can be considered as a primary frequency standard since the locked frequency is
traceable to a physical constant. The absolute accuracy of the wavelength is limited only by the
measurements (literature values or measurements made at standards bodies) made on the energy
level and the small jitter inherent in the locking process.
1.2 Application
A typical application for the Clarity laser is to provide an extremely accurate and stable wavelength
standard in the DWDM band. This can be used as a calibration source for an OSA (optical spectrum
analyzer) or to verify operation of a wavelength meter. Most wavelength meters are actually frequency
ratio meters which measure the wavelength of the unknown signal as a ratio to the built-in standard.
Generally the built-in standard is a helium neon laser. These lasers are available with absolute
frequency accuracy nearly as accurate as the Clarity but the wavelength at 632nm is very far from the
DWDM band. Vendors of wavelength meters have developed correction algorithms to compensate for
the difference of index of refraction of air and other factors that might affect the transfer of this accuracy
to the DWDM band by the wavelength meter. These techniques all add a measure of uncertainty. The
Clarity provides a means, heretofore unavailable, to verify the correct operation of a wavemeter up to
its full capabilities with a signal in the DWDM band.
Another application of the laser is in the area of interferometric sensing. Fiber optic based
hydrophones, for example, require a laser with very narrow linewidth and stable wavelength. The
Clarity laser is available with a semiconductor laser with a linewidth of <30KHz. Other interferometric
applications are surface roughness characterization, down-hole sensing, LIDAR wind detection, and
perimeter security. For applications requiring extremely narrow kHz linewidth the Clarity platform is can
be offered with extended cavity lasers from several vendors. Here we can combine the very narrow
linewidth of the extended cavity laser with the long term stability of a gas line. The Clarity can be made
available at several different wavelengths determined by the absorption spectra of the gases suitable
for your application. Also contact factory for inquiries relating to any OEM applications as a low cost
board level product is also available.
The Clarity laser is also a useful tool in gas sensing. We can provide a laser locked to many species of
gases in the near IR region. This includes the greenhouse gases carbon dioxide, methane, and nitrous

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oxide and other species such as hydrogen fluoride, hydrogen chloride, hydrogen sulphide, carbon
monoxide, acetylene, ammonia, and others. The absorption line can be scanned under software
control and along with the electrical output of the gas cell the laser is an extremely useful tool in gas
sensing and gas sensing system development.
1.3 Visual and Operational Inspection
The Clarity laser is packed in a carton designed to give adequate protection during shipment. If the
outside of the shipping carton is damaged, notify your shipping department and carrier immediately. If
the external packaging is not damaged carefullyremove the contents. The contents should include:
Clarity laser
Power cord
Cal certificate and manual (manual maybe emailed separately)
BNC rear interlock short
1.4 Options and Accessories
The Clarity laser is available in a number of different wavelengths; check with factory for the latest
availability. The unique architecture used allows some tuning of the wavelength while still being
referenced to an unchanging molecular energy level. This allows for wavelengths to be offered that are
exactly on an ITU DWDM grid location (Note only available on some grid locations).The wavelength
option is designated by the center wavelength. For example:
Clarity-PFR-1530
Clarity-NLL-1542
Clarity-NLL-1542-HP
Explanation:
PFR Stands for Precision FrequencyReference.
NLL Stands for narrow linewidth laser. This includes PFR functionality
1530 The laser wavelength in nm.Standard versions are:
1530nm locked to the P9 line of C12 acetylene
1542nm locked to the P16 line of C13 acetylene
1312nm locked to the P3 line of hydrogen fluoride
[other wavelengths available –consult factory]
HP High power option for the NLL, includes PM fiber output at >30mW
1.5 Operating Environment
The Clarity laser should be used in an area which satisfies the following conditions:
Ambient Temperature: 0C to 50C (operating temperature)
Relative Humidity: <85% non-condensing
Low noise area. While the Clarity laser is designed for noise immunity the best
performance will be achieved in a low EMF area. Please use a noise line filter in an area
where high noise is unavoidable