Santec OTF-930 User manual

OTF-930
Optical Tunable Filter
Operation Manual

OTF-930 Operation Manual
Disclaimer
Every effort has been made to ensure the information contained in this manual is accurate and easily
understandable. Santec shall not, however, be liable for errors contained herein, or for incidental or
consequential damages in connection with the use of this material.
Copyright 2005, Santec Corporation, Japan. No part of this document may be reproduced,
stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical,
photocopying, recording, or otherwise without the prior written permission of Santec Corporation,

Optical Tunable Filter OTF-930
This manual explains the operation and safety features of the OTF-930 Optical Tunable Filter. 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.
DANGER!!
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
This indicates a dangerous procedure that could result in serious injury or
This mark is used on the equipment as a warning of danger.
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 indicates there is a danger due to laser radiation. Do not look directly at
the laser beam or look at the beam by eye through any optical instrument.
CAUTION

OTF-930 Operation Manual
About This Manual
1. Introduction
2. Specications
3. Features
3.1. Wavelength Range
3.2. Peak Search Function
3.3. Optical Power Monitor
3.4. Wavelength Calibration
4. Principle of Operation
5. Panel Descriptions
5.1. Front Panel
5.2. Rear Panel
5.2. Bottom Panel
6. Safety Information
6.1 Mains Voltage
6.2 Installation
6.3 Safe Operation
Contents

Optical Tunable Filter OTF-930
7. Operation Procedures
7.1. Power On / Off
7.2. Optical Fiber Connection
7.3. Setting Parameters
7.3.1. Setting using the Numeric Keypad
7.3.2. Setting using the Up / Down Arrow Keys
7.4. Wavelength Tuning / Setting
7.5. Filter Bypass Control
7.6. Peak Search
7.6.1. Setting Scan Range
7.6.2. Performing a Scan
7.7. Changing Display Units
7.8. Wavelength Offset (Calibration)
7.9. Storing Wavelength Offset & Parameter Settings
7.10. Restoring the Unit to Factory Default Settings
8. Communication Interfaces
8.1. GPIB Control
8.2. RS-232C Control
8.3. Control Commands
9. Example Programs
9.1. GPIB Program
9.2. RS-232C Program

OTF-930 Operation Manual
10. Care and Maintenance
10.1. Care
10.2. Maintenance
10.3. Cleaning the Optical Connectors
10.4. Changing the Fuse
10.5. Inspection/Calibration
11. Re-packing and shipping
11.1. Re-packing
11.2. Packing instruction
11.3. Shipping
12. Troubleshooting
13. Warranty

Optical Tunable Filter OTF-930
1-1
1Introduction
The OTF-930 has been designed to achieve exceptional optical performance whilst
maintaining exibility and ease of use. It incorporates a multi-layer dielectric lter that has
been carefully fabricated to ensure high optical quality and long term stability. In addition,
the lter uses Santec’s unique linear sliding tuning technology which enables a wide tuning
range to be achieved, whilst the optical properties such as bandwidth, insertion loss, and
polarization dependent loss (PDL) are all wavelength independent.
The OTF-930 boasts a very exible peak search function that enables it to be used when
even multiple signals are present. This feature, combined with the GPIB and RS-232C
interfaces, enable the lter to be used in a wide range of applications. The OTF-930 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
OTF-930 Operation Manual

Optical Tunable Filter OTF-930
2-1
2 Specications
A wide range of lter types are available. The above table shows an example specication using a
nominal 1.2nm bandwidth (12 type), single cavity, double cascade lter. Please see the serial number
label on the rear panel for details of the lter type and options installed.
The following items should be supplied with your OTF-930 unit:
1. 2 power switch keys
2. Power supply cable
3. Operation Manual
4. Test report
Min. Typ. Max.
Filter Type -
Wavelength Range nm 1530 1610
Insertion Loss dB 2.0 2.5
Bandwidth at -3dB nm 0.8 0.9 1.0
Bandwidth at -20dB nm - - 4.5
Wavelength Resolution nm - - 0.01
Wavelength Accuracy nm -0.1 - 0.1
Temperature Dependence pm / ºC - 2 -
Power Monitor Relative Accuracy*1 dB -0.1 - 0.1
PDL dB - 0.1 0.2
PMD*3 ps - - 0.1
Return Loss dB 45 50 -
Max.Optical Input Power*2 dBm - - 20
Fiber Type -
Connector Type -
Communication Interface -
Size (w x h x d) mm
Weight kg
Supply Voltage V
Maximum Power VA
Operating Temperature ºC
Operating Humidity %
Operating Height above sea level m
Storage Temperature ºC 0 - 50
Storage Humidity %
Polution Degree **
*1 Output Power : -20 ~ +10dBm *2 Damage Threshold *3 Design Guaranteed Performance
FC/SPC (FC/APC, SC/SPC, SC/APC options)
SMF
12-S2: 12 Type, Single Cavity, Double Cascade
AC100~240V ±10%
4
210 x 80 x 300
Item Unit
GPIB, RS-232C
2
35
<2000
<80 (Non condensing)
20 to 30
<80 (Non condensing)
Value

2-2
OTF-930 Operation Manual

Optical Tunable Filter OTF-930
3-1
3Features
The Peak Search function provides automatic searching and selection of the wavelength with the
greatest optical power. The function operates by sweeping the lter through a specied wavelength
range whilst continuously monitoring the optical power. On completion of the search the filter
automatically moves to the wavelength with greatest optical power. The Peak Search Function has
two modes. In the standard mode the OTF-930 sweeps through the specied wavelength range in
0.001nm steps. A peak is thus selected with high accuracy, and by selecting a suitable scan range the
function can even be used to select a single wavelength from a comb of signals. In addition, a Rapid
Mode can also be programmed. In Rapid Mode an initial course wavelength sweep is performed
at 1nm intervals and this is followed by a ne wavelength sweep in 0.001nm steps over a range of
±1nm from the detected peak. The Rapid Mode thus enables a rapid scan over a broad wavelength
range to be achieved whilst maintaining the high resolution and accuracy.
3.2. Peak Search Function
3.1. Wavelength Range
The OTF-930 can be supplid in a variety of factory preset congrations. Internally,the instrument has
two individual lter elements. These can be seleced to give an 80nm tuning range, or a 40nm tuning
range with two different lter types. The most common congraion is 80nm to cover the C and L
wavelength bands (1530-1570nm) as used in dense wavelength division multiplexed communication
systems.
Optical power monitoring is realized by tapping the optical signal using a coupler behind the lter
element and monitoring this using a photodetector. Compensation for the wavelength sensitivity of
the photodetector is carried out automatically.
3.3. Optical Power Monitor

3-2
OTF-930 Operation Manual
The OTF-930 is calibrated in the factory and should not usually require adjustment. The wavelength
calibration feature enables a user to recalibrate the unit should this become necessary. An adjustment
of up to ±1.0nm is possible. If the device requires an adjustment greater than this there may be a
more serious problem and we recommend that you contact Santec’s technical support division.
3.4. Wavelength Calibration

Optical Tunable Filter OTF-930
4-1
4Principle of Operation
The gure above shows a schematic diagram of the OTF-930. Two lter elements, each with a
40nm wavelength range, are mounted on a stepper motor driven slider. Light is collimated by a lens
and passes directly through the lter. The slider is automatically controlled to provide seemless
wavelength tuning over the full 80nm range. The ltered light is coupled back into a ber and a
small portion is tapped onto a photodetector. This enables accurate power monitoring of the ltered
CPU
Communication
Interface
Display
Motor
IN
PD
OUT
GPIB
RS-232C
L1
FL1
L1, L2 :Lens
FL1,FL2:Filter
L2
FL2
Slider

OTF-930 Operation Manual
4-2

OPTICAL TUNABLE FILTER OTF-930
5-1
5-1. Front Panel
5
(1) Wavelength Display Panel
Displays the current wavelength setting in nm
(2) Optical Power Display Panel
Displays the optical output power. The measurement unit can be set to either mW or dBm and
is toggled by pressing the mW/dBm selector key (5). The power is calibrated according to the
wavelength setting shown in the Wavelength Display Panel (1).
(3) Optical Power Unit Indicator
Indicates unit of optical output power (mW or dBm).
(4) Wavelength Unit Indicator
Indicates units of displayed wavelength (nm).
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11)
(25) (24) (23) (22) (21) (20) (19) (18) (17) (16) (15) (14) (13) (12)
(26)
(27)
(28)
(29)
Panel Descriptions

5-2
OTF-930 Operation Manual
(5) Optical Power Unit Selector Key
Toggles the optical power measurement unit between mW and dBm.
(6)(7) Up / Down Arrow Key
Increments / decrements value of selected digit by one unit.
(8) Numeric Keypad
Allows direct input of parameters in setting modes.
(9) Clear Key (CL)
Clears values when setting.
(10) Backspace Key (BS)
Moves cursor back one space when entering parameter using numeric keypad.
(11) Enter Key (ENT)
Registers the value entered via either Up / Down Arrow Keys or Numeric Keypad.
(12) Cancel Key (-)
Cancels direct input of parameters using numetric keypad.
(13) Optical Output Connector
The optical output connector is located behind a safety cover. The cover pulls down for use.
(14) Optical Input Connector
The optical input connector is located behind a safety cover. The cover pulls down for use.
(15) Cursor Key
Allows digit selection when using Up / Down Arrow Keys to set value.
(16) GPIB Local Key / GPIB Address Change Key (LOCAL)
a. Pressing this key when GPIB remote operation is active returns control to the front panel.
b. Pressing this key after pressing the SHIFT Key (21) enables the GPIB address and delimiter
to be changed. The GPIB address is rst displayed in the Optical Power Display Panel (2)
and can be changed using the Up / Down Arrow Keys (6)(7). Pressing the GPIB Local Key a
second time displays the GPIB delimiter which can be similarly changed using the Up / Down
Arrow Keys. Pressing the GPIB Local Key a third time returns control to normal operation.

OPTICAL TUNABLE FILTER OTF-930
5-3
(17) 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 GPIB Local Key (16).
(18) Calibration Key (CAL)
Allows an offset to be applied to the wavelength value displayed.
(19) Store Key
Stores the wavelength offset data to internal ash memory. This setting is then retained even
when power to the OTF-930 is switched off.
(20)(21) Shift Key with Indicator LED
Enables alternative operation of other key functions. The indicator LED lights when the Shift
Key is pressed and remains lit until a valid function key is pressed or until the Shift Key is
pressed a second time. Pressing the Shift Key a second time cancels its operation. Valid key
combinations are:
a. Shift + Local: Allows GPIB Address and Delimiter to be set.
b. Shift + PS: Sets wavelength scan range for Peak Search function.
(22)(23) Option Key with Indicator LED
Not used.
(24) Serial Interface (SIF) Connector
Used for RS-232C communication.
(25) Power On / Off Key Switch
Operated using the power switch key, this is used to switch the unit on and off.
(26)(27) Disable Key with Indicator LED
Enables the lter to be removed from the beam. The LED blinks when this key is initially
pressed to indicate the lter is moving. The LED lights continuously when the lter is no
longer in the path of the beam. Pressing the key again returns the lter to its original position.
Again, the LED blinks when the lter is moving and the LED goes out when the lter has
returned to its original position.

5-4
OTF-930 Operation Manual
.
(28)(29) Peak Search (PS) Key with Indicator LED
1. Activates peak search function. Pressing this key during the search cancels
the operation. The LED indicates when peak search mode is active.
2. Pressing the key after pressing the SHIFT key enables the wavelength range
used for the peak search to be set.

OPTICAL TUNABLE FILTER OTF-930
5-5
5.2. Rear Panel
(1) Mains Connector Socket
(2) Fuse box
Pull out the fuse box, and replace with new fuses.
(1) (2) (5) (4)
(3)
(3) Serial Number Label
Indicates model number, serial number and options installed on each unit.
(4) GPIB Connector
(5) Slit
Slit for heat dissipation. It is important to leave at least 5 cm of space behind the OTF-930
unit to ensure proper ventilation and cooling.

5-6
OTF-930 Operation Manual
5.3. Bottom Panel
(1) (2)
(1) Slits
Slits for ventilation and cooling. It is important that the unit is used in a location which
allows
cool air to ow freely into the slits.
(2) Rubber Feet
The rubber feet provide mechanical isolation from external shocks and vibrations.
They also allow an air gap beneath the Slit (1) ensuring ventilation and cooling for the
instrument. The instrument should not be operated with the Rubber Feet removed.