Tektronix SD-44 User manual

Instruction Manual
SD-44
Optical-to-Electrical Converter
071-0061-01

Copyright ©Tektronix, Inc. All rights reserved.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.
Printed in the U.S.A.
Tektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070–1000
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

WARRANTY
Tektronix warrants that the products that it manufactures and sells will be free from defects in materials and
workmanship for a period of one (1) year from the date of shipment. If a product proves defective during this
warranty period, Tektronix, 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 notify Tektronix of the defect before the expiration
of the warranty period and make suitable arrangements for the performance of service. Customer shall be
responsible for packaging and shipping the defective product to the service center designated by Tektronix, with
shipping charges prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to a
location within the country in which the Tektronix service center is located. Customer shall be responsible for
paying all shipping charges, duties, taxes, and any other charges for products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate
maintenance and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage
resulting from attempts by personnel other than Tektronix representatives to install, repair or service the product;
b) to repair damage resulting from improper use or connection to incompatible equipment; c) to repair any
damage or malfunction caused by the use of non-Tektronix supplies; or d) to service a product that has been
modified or integrated with other products when the effect of such modification or integration increases the time
or difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX IN LIEU OF ANY OTHER WARRANTIES, EXPRESS
OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. TEKTRONIX’
RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND
EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY.
TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR
THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

Service Assurance
If you have not already purchased Service Assurance for this product, you may do so at any time during the
product’s warranty period. Service Assurance provides Repair Protection and Calibration Services to meet your
needs.
Repair Protection extends priority repair services beyond the product’s warranty period; you may purchase up to
three years of Repair Protection.
Calibration Services provide annual calibration of your product, standards compliance and required audit
documentation, recall assurance, and reminder notification of scheduled calibration. Coverage begins upon
registration; you may purchase up to five years of Calibration Services.
Service Assurance Advantages
HPriced well below the cost of a single repair or calibration
HAvoid delays for service by eliminating the need for separate purchase authorizations from your company
HEliminates unexpected service expenses
For Information and Ordering
For more information or to order Service Assurance, contact your Tektronix representative and provide the
information below. Service Assurance may not be available in locations outside the United States of America.
Name VISA or Master Card number and expiration
Company date or purchase order number
Address Repair Protection (1,2, or 3 years)
City, State, Postal code Calibration Services (1,2,3,4, or 5 years)
Country Instrument model and serial number
Phone Instrument purchase date

SD-44 Instruction Manual i
Table of Contents
General Safety Summary ii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contacting Tektronix iv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Getting Started 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard Accessories 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Options 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Accessories 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Basics 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Handling 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning Optical Connectors 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting Optical Signals 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Attenuating Optical Signals 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Performance Verification 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Required 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Zero 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DC Conversion Gain 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Noise Equivalent Power 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bandwidth/Frequency Response 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replaceable Parts 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ii SD-44 Instruction Manual
General Safety Summary
Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.
Only qualified personnel should perform service procedures.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.
Do Not Operate Without Covers. Do not operate this product with covers or panels
removed.
Wear Eye Protection. Wear eye protection if exposure to high-intensity rays or
laser radiation exists.
Do Not Operate With SuspectedFailures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.
Do Not Operate in Wet/DampConditions.
Do Not Operate in an Explosive Atmosphere.
Keep Product Surfaces Clean and Dry.
Terms in this Manual. These terms may appear in this manual:
WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.
Terms on the Product. These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read the
marking.
WARNING indicates an injury hazard not immediately accessible as you read the
marking.
CAUTION indicates a hazard to property including the product.
To Avoid Fire or
Personal Injury
Symbols and Terms

General Safety Summary
SD-44 Instruction Manual iii
Symbols on the Product. The following symbols appear on the product:
CAUTION
Refer to Manual
CAUTION
Static Sensitive

iv SD-44 Instruction Manual
Contacting Tektronix
Product
Support For application-oriented questions about a Tektronix measure- ment product, call toll free in North America:
1-800-TEK-WIDE (1-800-835-9433 ext. 2400)
6:00 a.m. – 5:00 p.m. Pacific time
Or contact us by e-mail:
[email protected]
For product support outside of North America, contact your
local Tektronix distributor or sales office.
Service
Support Contact your local Tektronix distributor or sales office. Or visit our web site for a listing of worldwide service locations.
http://www.tek.com
For other
information In North America: 1-800-TEK-WIDE (1-800-835-9433)
An operator will direct your call.
To write us Tektronix, Inc.
P.O. Box 1000
Wilsonville, OR 97070-1000

SD-44 Instruction Manual 1
Getting Started
The SD-44 is an optical-to-electrical (O/E) converter that converts an optical
input signal into an output voltage for display on either a high-speed oscillo-
scope or spectrum analyzer. The converter accepts optical signals from DC up to
15 GHz. The SD-44 O/E converter installs in any of the front panel compart-
ments of a Tektronix 11800 Series Digital Sampling Oscilloscope, the SM-11
Multichannel Unit, or the Tektronix CSA 803 Communications Signal Analyzer.
An optional stand-alone power supply is also available for the SD-44 O/E
converter (see page 20).
Figure 1 shows the front panel of the SD-44 O/E converter.
Optical signal
input connector
(FC/PC)
Screw lock knob
Electrical signal
output connector
(SMA)
GreenLED(power)
Figure 1: SD-44 front panel
The SD-44 O/E converter has an FC/PC receptacle for optical signal input and a
precision 3.5 mm connector for electrical signal output.
The following list highlights the key performance characteristics of the SD-44
O/E converter:
H1000 to 1650 nm wavelength response
H15 GHz Minimum Transducer Bandwidth
H35 mV/mW of DC conversion gain at 1310 and 1550 nm
For a complete list of specifications, see to page 10.

Getting Started
2SD-44 Instruction Manual
Standard Accessories
The following accessories are standard with every SD-44 O/E converter:
HHard case
HInstructions
HFC/PC to FC/PC 9 mm single-mode fiber jumper
HFC/ST, FC/SC, and FC/FC hybrid connectors
HRigid cable (SMA-to-SMA, 50 W)
HSMA terminator
HCertificate of traceable calibration
For a list of replaceable part numbers, see page 18.
Options
The following options are available at the time of purchase:
HOpt 95 Calibration data
HOpt C3 Three years calibration services
HOpt R3 Three years extended warranty
Optional Accessories
The following recommended accessories are available through Tektronix:
HFiber-optic cables and adapters with a variety of fiber types and connector
styles
H90/10 single-mode optical splitter with FC/PC connectors
HDIN to FC fibre optic hybrid connector
H10 dB in-line single-mode optical attenuator
HStand-alone power supply
For a list of part numbers, see page 18.

Getting Started
SD-44 Instruction Manual 3
Installation
Follow the instructions in this section to install the SD-44 O/E converter into the
Tektronix 11800 Series Digital Sampling Oscilloscope or CSA 803 Communica-
tions Signal Analyzer, or to connect it to the optional power supply for stand-
alone operation.
On the Tektronix 11800 Series Digital Sampling Oscilloscope or the CSA 803
Communications Signal Analyzer, the SD-44 O/E converter installs into any of
the front panel compartments.
NOTE. For the best performance, connect the SD-44 Optical-to-Electrical
Converter to the input of the sampling head using the rigid connector provided.
The sampling head must be in the compartment immediately to the right of the
O/E converter. See Figure 2.
Choose one of the following Tektronix sampling heads to connect to the output
of the O/E converter:
HSD-22 (recommended for lowest noise performance)
HSD-24
HSD-26
HSD-30
HSD-32
Use the following procedure to install the O/E converter and sampling head
modules:
CAUTION. The output of the O/E converter and the input of the sampling head
are subject to damage from electrostatic discharge (ESD). To prevent damage
from ESD, take the following precautions:
Always wear an anti-static wrist strap when handling a static sensitive
instrument.
Keep the short-circuit termination in place when moving or storing the
instrument. Remove the termination only to connect a cable.
Discharge the inner conductor of a loose, unterminated cable before connecting
it to the instrument.
11800 or CSA 803 Series

Getting Started
4SD-44 Instruction Manual
1. Switch off the measurement instrument.
2. Place the module in a compartment and slowly push it in with firm pressure.
3. Once the module is seated, turn the screw shaft on the plug-in to tighten the
module in place.
4. Switch on the measurement instrument and check that all modules have
power.
5. Remove the termination on the output of the O/E converter and connect the
output to the lower input of the sampling head as follows.
a. Use the rigid connector if possible and install the shorter leg of the
connector on the sampling head. See Figure 2.
b. Align the SMA connectors carefully.
c. Use light, finger pressure to turn the nut. Do not turn the cable.
d. Tighten the nut lightly with a wrench. For best repeatability and to
prolong the life of SMA connectors, use a torque wrench and tighten
the connection to the range of 7 to 10 lb-in (79 to 112 N-cm).
Shorter leg
Samplinghead
O/E converter
Figure 2: Using the rigid connector

Getting Started
SD-44 Instruction Manual 5
NOTE. On the CSA803 series, the O/E converter will work in any of the
power-only or sampling head compartments, but the sampling head must be
installed in one of the two sampling head compartments on the right. See
Figure 3.
SD-44 or
sampling head
SD-44 only
(power-only
compartments)
Figure 3: Front panel compartments in a CSA803 CommunicationsSignal Analyzer

Getting Started
6SD-44 Instruction Manual
The optional power supply kit (Figure 4) allows the user to power the SD-44
O/E converter by itself. This allows the O/E converter to operate with other types
of measurement instruments independent of a CSA or 11800 series mainframe.
The part number for the kit is on page 20.
Figure 4: Installation with optional power supply kit
Optional Power Supply

SD-44 Instruction Manual 7
Operating Basics
To prolong the life of the SD-44 O/E converter observe the following handling,
cleaning, and operating instructions.
Handling
Handle the SD-44 O/E converter carefully at all times.
CAUTION. To avoid damaging the SD-44 O/E converter, take the following
precautions:
Do not drop the O/E converter since damage and misalignment of the photo-
diode optical assembly can result. Store the O/E converter in a secure location
when not in use.
Replace the protective caps on the input and output connectors when the O/E
converter is not in use.
Cleaning Optical Connectors
Small dust particles and oils can easily contaminate optical connectors and
reduce or block the signal. Take care to preserve the integrity your connectors by
keeping them free of contamination.
CAUTION. To prevent loss of optical power or damage to the optical connectors,
keep the connectors clean at all times.
When cleaning the connectors with a swab, use gentle circular motions. Use only
high quality cleaning supplies that are non-abrasive and leave no residue.
To reduce the need for cleaning, immediately replace protective caps on the
optical connectors when not in use.

Operating Basics
8SD-44 Instruction Manual
Use the following items to clean the optical connectors:
Hclean compressed air
Hfiber-optic cleaning swabs
Hisopropyl alcohol
To clean the optical connectors, follow these steps:
1. Hold the can of compressed air upright and spray the can into the air to purge
any propellant.
2. Spray the clean compressed air on the connectors to remove any loose
particles or moisture.
3. Moisten a clean optical swab with isopropyl alcohol then lightly swab the
surfaces of the connectors.
4. Spray the clean compressed air on the connectors again to remove any loose
particles or isopropyl alcohol.
NOTE. Cleaning kits for optical connectors are available from a number of
suppliers.
Connecting Optical Signals
Attach the fiber optic cable with an FC/PC connector to the FC/PC input
receptacle as follows:
1. Carefully align the keyway on the receptacle with the key on the connector.
2. Tighten the nut lightly with finger pressure only.
The input of the SD-44 O/E converter can couple to optical fibers with a core
diameter of up to 9 mm. Alternate types can be coupled by use of an FC-FC
jumper and the FC-FC, FC-ST, FC-SC adapters. (Refer to Optional accessories
on page 20.)
CAUTION. To maintain the high performance (low return loss) of the optical
interface, connect an adapter and cable between the input of the O/E converter
and the device under test. When you make connections to other devices, leave the
adapter and cable in place to protect the optical interface of the O/E converter
from wear.
Equipment Required
Procedure

Operating Basics
SD-44 Instruction Manual 9
If you connect fiber cores larger than 9 mm, the O/E converter may still couple
light, but the mismatch in core diameter will cause lower conversion gain and
higher insertion loss.
Attenuating Optical Signals
To keep the optical input power to an appropriate level, it may be necessary to
attenuate the optical signal.
CAUTION. To avoid damaging the optical input of the SD-44 O/E converter,
attenuate optical signals to less than 5 mW average power or 10 mW peak power
at the wavelength with highest relative responsivity.
For linearity and measurement accuracy, attenuate the peak-to-peak swing of
signal to within the specified performance of 200 mWp-p.

10 SD-44 Instruction Manual
Specifications
This section contains the specifications for the SD-44 Optical-to-Electrical
Converter. All specifications are guaranteed unless noted as “typical.” Typical
specifications are provided for your convenience but are not guaranteed.
Specifications marked with the nsymbol have corresponding checks in the
Performance Verification section on page 12.
Table 1: SD-44 Specifications
Specification Description
Effectivewavelength range, typical 1000 nm to 1650 nm
nDCconversiongain ≥35 mV / mW at 1310 nm ±20 nm and 1550 nm ±20 nm
Relative responsivity, typical See Figure 5
Absolutemaximumnondestructive optical
input 5 mW average power; 10 mW peak power at wavelength with highest relative responsivity
nBandwidth DC to 15 GHz (≥– 6 dB electrical power into 50 W) for signals < 2 mWp-p
Inputfiberdiameter Accepts 9 mm singlemode diameter; Numerical Aperture (NA) ≤0.20
Internalfiberdiameter core: 9 mmsingle-modefiber
cladding: 125 mm
Fiberconnectorstyle femaleFC/PC
Optical return loss > 30 dB typical; > 28 dB minimum when external mating fiber is also PC style
nNoiseequivalentpower ≤15 pWńHz
Ǹelectrical output noise when terminated into 50 W
Impulseresponsewidth ≤30 ps FWHM (Full Width Half Maximum)
Aberrations ≤10%p-p total
nOutputzero ≤1 mV
External terminationimpedance 50 W±2 W
Temperature Operating: +10_C to +40_C
Non-operating:–55_C to +75_C
Humidity 75%non-condensing
Altitude Operating: 4,572 m (15,000 ft)
Non-operating:15,240m(50,000ft)

Specifications
SD-44 Instruction Manual 11
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1.10
1000 1200 1400 1600
Wavelength (nanometers)
Relative conversion gain
Figure 5: SD-44 relative responsivity (normalized to 1310 nm)

12 SD-44 Instruction Manual
Performance Verification
Use the following procedures to verify the warranted specifications of the SD-44
Optical-to-Electrical Converter. Before beginning these procedures, see page 17
and photocopy the test record and use it to record the performance test results.
The recommended certification interval is one year.
These procedures test the following specifications:
HNoise equivalent power
HOutput zero
HDC conversion gain
HBandwidth/Frequency Response
Equipment Required
Table 2 lists the equipment required to perform the performance verification
procedure. The types and quantities of connectors may vary depending on the
specific equipment you use.
Table 2: Test equipment
Description Minimumrequirements Example product
Optical power meter with
headandadapters Accuracy > 2.5%, resolution > 5 pW, Max power > 1 mW, cali-
brated from 700 nm – 1600 nm
HP 8153A with
HP811532head
1310 nm cal source output > 200 W1,
stability > 0.1 dB over 5 minutes,
modulated square wave @ 10 kHz
with off modulation at zero-light
level
Rifocs665R–PO
1550 nm cal source output > 200 W (CW)1,
stability > 0.1 dB over 5 minutes,
modulated square wave @ 10 kHz
with off modulation at zero-light
level
Rifocs666R–PO
RF power meter noise < .1 mV, BW > 4 GHz HP 436A with power sensor
HP8484A
1300 or 1550 nm impulse
generator pulse width < 6 ps Clark MXR ErFt picosecond1550laser