Santec PEM-340 User manual

PEM-340
Polarization Extinction Ratio Meter
Operation Manual

PEM-340 Operation Manual
Trademarks
Notes to Users
1) Copyright 2018, Santec Corporation. All rights reserved. No part of this Operation
Manual may be reproduced or transmitted in any form or by any means, electronic or
mechanical, for any purpose, without the prior written permission of Santec.
2) Information in this Operation Manual is subject to change without notice.
3) Information of this Operation Manual is prepared with careful examination, however,
in the event of any mistake, please contact us.
Notes in Bringing This Product Out of Japan
1) When this product is brought out of Japan, some laws or regulations of a destination
country may prohibit this product from being used there. In such countries, the use
of this product may lead to punishment. Please note, that in such cases Santec
Corporation shall not be held responsible in anyway.
2) When this product is exported (or brought out of Japan), and this product is
applicable to a strategic material specified in the “Foreign Exchange and Foreign
Trade Control Law”, then under law of the Japanese Government, an export permit is
required.
is a trademark of Santec Corporation.
PEM-340 is a trademark of Santec Corporation.

Polarization Extinction Ratio Meter PEM-340
This manual explains the operation and safety features of the PEM-340 Polarization Extinction Ratio
Meter. To ensure the safe operation of the instrument, and to prevent the risk of personal injury
and/or damage to the equipment we recommend that you read the manual fully before commencing
installation and operation. In particular Chapter 6 outlines the precautions necessary to ensure safe
operation. The following safety symbols are used throughout the manual and on the equipment to
indicate safety related information.
Packing Materials
The original packing materials are required to ensure the safe long term storage and safe
transportation of this equipment. It is recommended that all packing materials are kept for these
purposes.
This indicates a dangerous procedure that could result in serious injury or
death if not performed properly.
About This Manual
This indicates a hazardous procedure or danger that might result in injury or
that could damage the equipment if proper precautions are not taken.
This mark is used on the equipment as a warning of danger.

PEM-340 Operation Manual
About This Manual
1. Introduction
2. Product Composition
3. Specications
4. Features
4-1. Real Time Display
4-2. Offset Cancel
4-3. Communication Interfaces
4-4. Analog Data Output
4-5. Stopped Polarizer Function
4-6. High Speed Measurement
5. Principle of Operation
6. Panel Descriptions
6-1. Front Panel
6-2. Rear Panel
7. Installation
7-1. Operating Environments
7-2. Power Supply
8. Operation Procedures
8-1. Power On/OFF
8-2. Optical Fiber Connection
Contents

Polarization Extinction Ratio Meter PEM-340
8-3. Offset Cancel
8-4. Changing Display Units
8-5. PER Averaging Function
8-6. Setting GP-IB address and Delimiter
8-7. Setting Wavelength Range and Measurement Speed
8-8. Analogue Output
8-9. Changing the Optical Connector
9. Communication Interfaces
9-1. GPIB Control
9-1-1. Connection
9-1-2. GPIB function
9-2. RS-232C Control
9-3. Control Commands
9-4. Example Program
9-4-1. GPIB Program
9-4-2. RS-232C Program
10. Care and Maintenance
10-1. Care
10-2. Maintenance
10-3. Replaceing Fuses
10-4. Inspection/Calibration
11. Re-packing and shipping
11-1. Re-packing
11-2. Shipping
12. Troubleshooting
13. Warranty

PEM-340 Operation Manual

Polarization Extinction Ratio Meter PEM-340
1-1
1Introduction
The PEM-340 Polarization Extinction Ratio Meter provides accurate, real-time information about
the polarization state of light in an optical ber. It can be used as a general purpose measuring
instrument but has been designed, in particular, to enable the accurate and rapid alignment of
polarization maintaining bers to optical components. The rotating polarizer design, coupled with a
high sensitivity detector enable the PEM-340 to measure high linear polarization extinction ratios, of
up to 50dB, with a 2.5Hz refresh rate.
The PEM-340 simultaneously displays values for polarization extinction ratio (PER), optical
power and polarization angle. These are the three critical parameters required for the alignment of
polarization maintaining ber to optical components. In addition, the PEM-340 has full support for
GPIB and RS-232C communication interfaces together with an analogue data output. These features
provide the unit with unrivalled exibility for integration into automatic measurement and automatic
ber alignment systems.
The PEM-340 is easy to use, but to obtain the most from your unit we recommend that you read
this manual fully and become familiar with its contents prior to operation. We hope that you will be
satised with your purchase.

1-2
PEM-340 Operation Manual

Polarization Extinction Ratio Meter PEM-340
2-1
2Product Composition
PEM-340 Body (1)
Power Key (1) Power Cord (1)
Inspection report (1)
AIF Exclusive Use Cable (1)
Operation Manual 1
The Photonics Pioneer

2-2
PEM-340 Operation Manual

Polarization Extinction Ratio Meter PEM-340
3-1
3Specications
* 1： Temperature: 20-30℃, Measurement Speed: 2.5Hz
* 2： Calibrated wavelength: 1310nm / 1550nm
* 3： Measurement Speed: 2.5Hz
* 4： SPC: Super Physical Contact, APC: Angled PC
Normal power High power
Category
Wavelength Range
PER Dynamic Range
PER Range
PER Resolution
PER Accuracy *
1
Input Power Range
Power Resolution
Power Accuracy *
2
Polarization Angle Resolution *
3
Polarization Angle Accuracy
Measurement Speed
Interface
Optical Connector
Connector Polish
Operating Temperature
Size (w) x (D) x (H)
Weight
Supply Voltage
Maximum Power Consumption
Unit
dB
dB
dBm
dB
dB
deg
deg
sec
-
-
-
degC
mm
kg
V
W
1260-1630
-
0 to 40
0 to 30
0 to 20
0 to 50
0 to 40
0 to 30
0 to 20
-5～+10dBm
-15～+10dBm
-25～+10dBm
-35～+10dBm
-
-5～+20dBm
-15～+20dBm
-25～+20dBm
0.01
<±0.3
0.01
<±0.3
0.12
<±0.45
0.1/ 0.2/ 0.4
GP-IB, RS-232C
FC, SC or LC
SPC or APC *
4
0-40
210x300x80
3
AC100-240
35
50 40
-25～+20
-40～+10
PER < 30dB
nm
dB
dB

3-2
PEM-340 Operation Manual

Polarization Extinction Ratio Meter PEM-340
4-1
4Features
An Offset Cancel function is provided to enable compensation for the dark current of the
photodetector. This provides improved accuracy and greater dynamic range even when low optical
powers are used.
4-2. Offset Cancel
4-1. Real Time Display
The PEM-340 displays simultaneously, and in real time, values for the three critical parameters
required for the alignment and characterisation of polarization maintaining ber and polarization
ber pigtailed components. These are the polarization extinction ratio (PER), optical power and
polarization angle. In addition, the optical power can be displayed in units of mW or dBm.
The PEM-340 can be used as a stand alone bench-top type measurement instrument. However, it
also boasts industry standard GPIB and RS-232C interfaces through which the unit can be fully
controlled and through which all parameters can be monitored. The PEM-340 is thus suitable
for automated measurements in production environments and for integration into fully automatic
alignment systems.
4-3. Communication Interfaces
In addition to the communication interfaces described above, the PEM-340 has an analogue output
for monitoring of all the measured parameters. These signals are particularly useful as feedback
signals for the control loops of automated alignment systems. As an option, an output monitoring
the signal directly from the photodetector can also be provided.
4-4. Analogue Data Output

4-2
PEM-340 Operation Manual
The PEM-340 measures PER using a rotating polarizer. In some circumstances, such as the
automatic alignment of the lateral orientation of an optical ber to a laser light source, it is useful
to be able to stop the polarizer and measure the optical power with a faster response time than the
10Hz rotation will allow. The Stopped Polarizer Function provides this exibility and enables the
polarizer to be stopped at the angle of either maximum or minimum power transmission.
4-5. Stopped Polarizer Function
To provide additional exibility the PEM-340 can operate at one of three measurement speeds. The
default 2.5Hz measurement speed is recommended as it provides the highest dynamic range for both
PER and optical power. However, when required, the measurement speed can be increased to either
5 or 10Hz.
4-6. High Speed Measurement

Polarization Extinction Ratio Meter PEM-340
5-1
5Principle of Operation
The above diagram shows the design of the PEM-340 unit. The optical ber is connected through
the input connector. The light from the fiber is then collimated by a lens, and after passing
through a rotating polarizer is incident on the photodetector.
0
180
1 measurement period
max
min
Optical Power
Polarizer Angle (deg)

PEM-340 Operation Manual
5-2
After amplification the detected signal is converted to a digital format to enable the measured
parameters to be calculated by the unit's microprocessor. The diagram on the previous page shows
the sine-wave signal obtained as the polarizer rotates. One measurement period corresponds to a
180˚ rotation of the polarizer. PER is calculated as the ratio of the maximum and minimum signals
in any one measurement period and the polarization angle is determined by detecting the position of
the polarizer at minimum transmission. The PEM-340 displays a polarization angle of zero when
the polarization axis is vertical and aligned with the alignment notch of the input connector.

Polarization Extinction Ratio Meter PEM-340
6-1
6-1. Front Panel
6Panel Descriptions
(1) PER Display Panel
Displays the value for polarization extinction ratio (PER) in dB.
(2) Optical Power Display Panel
Displays the optical power. The measurement unit can be set to either mW or dBm and is
toggled by pressing the Optical Power Unit Selector Key (5).
(3) Optical Power Unit Indicator
Indicates unit of optical output power (mW or dBm).
(4) Polarization Angle Display Panel
Indicates the polarization angle of the light from the optical input in degrees. The angle is
measured with respect to the alignment notch on the optical connector; i.e. a value of zero is
given when the polarization axis is vertical and aligned with the alignment notch.
(1) (2) (3) (4) (5)
(12) (11) (10) (9) (8) (7) (6)

6-2
PEM-340 Operation Manual
(5) Optical Power Unit Selector Key
Toggles the optical power measurement unit between mW and dBm. This key is also used when
setting the GPIB address and GPIB delimiter.
(6) Optical Input Connector
This connector is used to input light. When using the offset cancel function, please execute the
offset cancel after certainly covering the optical input connector with a connector cap. The optical
input connector is FC / SC conversion type. Connection of the optical ber with dust and dirt on
the end of the optical connector of PEM-340 cause loss of optical input, therefore, please clean the
connector periodically.
(8-9. Changing the Optical Connector)
(7) [LOCAL] Key GPIB local /address change
a. Pressing this key when GPIB remote operation is active returns control to the front panel.
b. When this key is pressed for two seconds continuously the GPIB address and GPIB delimiter
setting mode is entered. The PER Display Panel (1) shows the GPIB address which ashes
to indicate that it can be changed using the Optical Power Unit Selector Key (5). Pressing
the [LOCAL] key a second time causes the GPIB delimeter setting shown in the Polarization
Angle Display Panel (4) to flash. Similarly, this can be changed using the Optical Power
Unit Selector Key (5). Pressing the [LOCAL] key a third time saves the displayed values and
returns control to normal operation.
c. Pressing this key when the power to the PEM-340 is first switched on sets the RS-232C
delimiter to CR (carriage return).
(8) GPIB Remote LED
Indicates GPIB remote operation is active. When active the front panel keys become inoperative.
To return control to the front panel press the [LOCAL] key (7).
(9) [MENU] Key
GP-IB Address/Delimiter Setting,Measurement wavelength,measurement speed setting.

Polarization Extinction Ratio Meter PEM-340
6-3
(10) [ZERO] Key (Offset Cancel)
a. Enables compensation for the dark current of the photodetector. A cover should be placed
over the optical input connector to prevent any stray light entering the unit before this button
is pressed.
b. Pressing this key when the power to the PEM-340 is rst switched on sets the RS-232C
delimiter to LF (line feed).
(11) Serial Interface (SIF) Connector
Used for RS-232C communication.
(12) Power On / Off Key Switch
Operated using the power switch key, this is used to switch the unit on and off.

6-4
PEM-340 Operation Manual
(1) Analogue Interface (AIF) Connector
Provides analogue output of PER, Optical Power and Polarization Angle.
(2) Mains Connector Socket
(3) Fuse Housing
(4) Slit for Heat dissipation
There is a cooling fan inside at this location. Please do not cover the slit.
The device needs at least 5cm of space for proper ventilation and cooling.
(5) GPIB Connector
(6) Serial Number Label
Indicates model number, serial number and options installed on each unit.
(2) (3) (4) (1) (5) (6)
6-2. Rear Panel