Tektronix SD-48 User manual

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Instruction Manual
SD-48
Optical-to-Electrical Converter
071-0207-00

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.

SD-48 Instruction Manual i
Table of Contents
General Safety Summary iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contacting Tektronix v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Getting Started 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard Accessories 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Options 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Accessories 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Basics 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Handling 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning Optical Connectors 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting Optical Signals 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Attenuating Optical Signals 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Performance Verification 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Required 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Zero 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DC Conversion Gain 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Noise Equivalent Power 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bandwidth/Frequency Response 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replaceable Parts 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contents
ii SD-48 Instruction Manual
List of Figures
Figure 1: SD-48 front panel 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2: Using the rigid connector (all sampling heads except
SD-32) 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3: Using the rigid connector and V–K adapter (SD-32
sampling head only) 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4: Front panel compartments in a CSA803
Communications Signal Analyzer 6. . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 5: Installation with optional power supply kit 7. . . . . . . . . . . . .
Figure 6: SD-48 relative responsivity (normalized to 1310 nm) 12. . . . .
Figure 7: Typical frequency response, Option RR (SD-48, OC-192
filter, and SD-22) 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 8: Setup for frequency response measurement, SD-48
standard configuration 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 9: Setup for frequency response measurement, SD-48
Option RR for OC192 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10: SD-48 replaceable parts 22. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 11: Standard accessories 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 12: Optional accessories 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 13: Optional power cords 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SD-48 Instruction Manual iii
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 Suspected Failures. 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
iv SD-48 Instruction Manual
Symbols on the Product. The following symbols appear on the product:
CAUTION
Refer to Manual
CAUTION
Static Sensitive

SD-48 Instruction Manual v
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

Contacting Tektronix
vi SD-48 Instruction Manual

SD-48 Instruction Manual 1
Getting Started
The SD-48 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 SD-48 O/E converter installs in any of the front
panel compartments 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-48 O/E converter (see page 24).
Figure 1 shows the front panel of the SD-48 O/E converter.
Optical signal
input connector
(FC/PC)
Screw lock knob
Electrical signal
output connector
(K-connector)
Green LED (power)
Figure 1: SD-48 front panel
The SD-48 O/E converter has an FC/PC receptacle for optical signal input and a
precision 2.92 mm K-connector for electrical signal output.
The following list highlights the key performance characteristics of the SD-48
O/E converter:
1000 to 1650 nm wavelength response
DC to 30 GHz typical transducer bandwidth
≥15 mV/mW of DC conversion gain at 1310 and 1550 nm
For a complete list of specifications, see to page 11.

Getting Started
2SD-48 Instruction Manual
Standard Accessories
The following accessories are standard with every SD-48 O/E converter:
Hard case
Instruction manual
FC/PC to FC/PC 9 mm single-mode fiber jumper
FC/ST, FC/SC, and FC/FC hybrid connectors
Rigid U-cable for sampling heads other than SD-32 (SMA-SMA, 50 W)
Rigid J-cable for SD-32 sampling head (SMA-SMA, 50 W, requires V-K
adapter)
Protective SMA terminator (installed on the electrical output)
SMA-SMA flexible cable
Certificate of traceable calibration
For a list of replaceable part numbers, see page 24.
Options
The following options are available at the time of purchase:
Opt D1 Calibration data
Opt D3 Three years calibration data
Opt C3 Three years calibration services
Opt R3 Three years extended warranty
Opt RR Add SMA in-line connector, OC-192 filter, and frequency
response graph (SD-22 electrical sampling head required but not included)
Optional Accessories
The following recommended accessories are available through Tektronix:
Fiber-optic cables and adapters with a variety of fiber types and connector
styles
90/10 single-mode optical splitter with FC/PC connectors
DIN to FC fiber-optic hybrid connector

Getting Started
SD-48 Instruction Manual 3
10 dB in-line single-mode optical attenuator
Electrical filters for 10 Gbs, 622 Mbs, and 155 Mbs
Stand-alone power supply
For a list of part numbers, see pages 24 and 25.
Installation
Follow the instructions in this section to install the SD-48 O/E converter into the
Tektronix 11800 Series Digital Sampling Oscilloscope or CSA803 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 CSA803
Communications Signal Analyzer, the SD-48 O/E converter installs into any of
the front panel compartments.
NOTE. For the best performance, connect the SD-48 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:
SD-22 (recommended for lowest noise performance)
SD-24
SD-26
SD-30
SD-32 (requires a V-K adapter and rigid J-cable, see Figure 3)
11800 or CSA 803 Series

Getting Started
4SD-48 Instruction Manual
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.
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. On all sampling heads except the SD-32, use the rigid connector and
install the shorter leg of the connector on the sampling head.
See Figure 2.
b. On the SD-32 sampling head, use the rigid connector and install the
shorter leg of the connector on the sampling head with a V–K adapter.
See Figure 3. (The V-K adapter is a standard accessory of the SD-32. If
you do not have a V–K adapter, refer to the list of optional accessories at
the end of this manual.)
c. Carefully align the SMA connectors on both ends of the rigid cable.
d. To avoid damaging the connectors on the SD48 or the sampling head,
alternately tighten the threads of each end of the rigid cable one turn at a
time until they are tight enough to enough to use a wrench.
e. Tighten each 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).

Getting Started
SD-48 Instruction Manual 5
Shorter leg
Sampling head
O/E converter
Rigid U-cable
(174-3828-00)
Figure 2: Using the rigid connector (all sampling heads except SD-32)
V-K adapter
(011-0157-00)
Rigid J-cable
(174-3976-00)
Shorter leg
SD-32 sampling head
O/E converter
Figure 3: Using the rigid connector and V–K adapter (SD-32 sampling head only)

Getting Started
6SD-48 Instruction Manual
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 4.
SD-48 or
sampling head
SD-48 only
(power-only
compartments)
Figure 4: Front panel compartments in a CSA803 Communications Signal Analyzer

Getting Started
SD-48 Instruction Manual 7
The optional power supply kit (Figure 5) allows the user to power the SD-48
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 24.
Figure 5: Installation with optional power supply kit
Optional Power Supply

8SD-48 Instruction Manual
Operating Basics
To prolong the life of the SD-48 O/E converter observe the following handling,
cleaning, and operating instructions.
Handling
Handle the SD-48 O/E converter carefully at all times.
CAUTION. To avoid damaging the SD-48 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
SD-48 Instruction Manual 9
Use the following items to clean the optical connectors:
clean compressed air
fiber-optic cleaning swabs
isopropyl 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-48 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 24.)
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