COMMUNICATIONS COMPONENTS
Key Features Low insertion loss
Wide attenuation slope range
Available in low and high contrast variants
Available in positive or negative slope variants
Low tuning voltage
Mountable on a PCB
The JDSU variable slope attenuator (VSA) equalizes uneven gain profiles inherent
to the use of optical amplifiers. The VSA is Telcordia GR 1209 and 1221 compliant
and uses hermetic sealing for increased resistance to environmental extremes. It is
available in low contrast and high contrast variants, and offers excellent positive
or negative slope optical performance in either the C or L bands.
The attenuation slope is precisely tuned using a stepper motor driven by an
external IC driver. The stepper motor adjusts the slope in small, uniform step
sizes, thus providing high resolution. The VSA is compact in size and can easily be
mounted on a printed circuit board (PCB). It requires minimum voltage. The
electrical pins extrude from the bottom of the package.
The spectral diagram on next page shows the transmission spectrum after passing
through the VSA. Both positive and negative slope profiles are available.
Applications
Remove cumulative error function
from amplifiers and filters
Correct variations in amplifier gain
profile due to add-drop
multiplexing and Raman effect
Balance channel power in
reconfigurable networks
Compliance
Telcordia GR 1209 and 1221
Variable Slope Attenuators
VSA Series
NORTH AMERICA:800 498-JDSU (5378) WEBSITE:www.jdsu.comWORLDWIDE:+800 5378-JDSU
(Note: Negative slope and low contrast variant)Performance
2
VSA SERIES
Specifications
Parameter High Contrast Low Contrast
Optimized wavelength range
C band 1530 to 1560 nm 1528 to 1565 nm
L band 1570 to 1610 nm 1568 to 1609 nm
Insertion loss at minimum slope1,2 Maximum 1.3 dB 1.3 dB
Insertion loss at maximum slope1,2 Maximum 2.2 dB 2.0 dB
Loss contrast at maximum slope1Minimum 7.0 dB 4.0 dB
Minimum loss slope1Maximium 0.02 dB/nm 0.02 dB/nm
Linearity Maximum 1.0 dB (absolute) 0.5 dB (absolute)
Polarization dependent loss Maximum 0.25 dB 0.25 dB
Polarization mode dispersion 0.1 ps 0.1 ps
Return loss1Minimum 40 dB 35 dB
Repeatability3Typical 0.003 dB/nm 0.002 dB/nm
Resolution Typical 0.003 dB/nm 0.002 dB/nm
Backlash Typical 0.003 dB/nm 0.002 dB/nm
Fiber type SMF-28 with 900 µm buffered jacket or 250 µm bare fiber
Maximum optical power Maximum 200 mW 200 mW
Dimensions (W x H x D)425 x 12 x 50 mm 25 x 12 x 50 mm
Operating temperature -5 to 70 °C -5 to 70 °C
Storage temperature -40 to 85 °C -40 to 85 °C
1. Excluding connectors.
2. Measured at λMIN for negative slope and at λMAX for positive slope.
3. With reference to potentiometer voltage at 25 °C.
4. Excluding strain relief and connector pins.
-7
-6
-5
-4
-3
-2
-1
0
1525 1530 1535 1540 1545 1550 1555 1560 1565 1570
Wavelength (nm)
Loss (dB)
Start +165
+250 +330
+415 +500
+580 +660
+750 End
NORTH AMERICA:800 498-JDSU (5378) WEBSITE:www.jdsu.comWORLDWIDE:+800 5378-JDSU
SMF-28 is a registered trademark of Corning Incorporated.
All statements, technical information and recommendations related to the products herein are based upon information believed to be
reliable or accurate. However, the accuracy or completeness thereof is not guaranteed, and no responsibility is assumed for any
inaccuracies. The user assumes all risks and liability whatsoever in connection with the use of a product or its application. JDSU reserves
the right to change at any time without notice the design, specifications, function, fit or form of its products described herein, includ-
ing withdrawal at any time of a product offered for sale herein. JDSU makes no representations that the products
herein are free from any intellectual property claims of others. Please contact JDSU for more information. JDSU and the JDSU logo are
trademarks of JDS Uniphase Corporation. Other trademarks are the property of their respective holders. ©2007 JDS Uniphase
Corporation. All rights reserved. 21025483 Rev. 002 10/05 VSA.DS.CC.AE
Ordering Information
For more information on this or other products and their availability, please contact your local JDSU account manager or
JDSU directly at 1-800-498-JDSU (5378) in North America and +800-5378-JDSU worldwide or via e-mail at
customer.service@jdsu.com.
Sample: VSA-0CNHC10NC
VSA SERIES
Code Contrast Level
HHigh contrast
LLow contrast
Code Fiber Type
C 9/125/900 fiber
E 9/125/250 fiber
Code Wavelength
CC band
LL band
Code Slope
NNegative slope
PPositive slope
VSA-0
Code Fiber Length1
10 1.0 m
15 1.5 m
Code Connector
NC No connector
FP FC/HPC
FA FC/APC
SCSC/HPC
SUSC/APC
SPST/HPC
MU MU
1. Other fiber length available upon request.
Reviewed February 2007