Extinction Ratio Meters

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Figure 1.1  Extinction Ratio Meter Responsivity

Features

• Polarization Extinction Ratio (PER) Measurements of Polarization-Maintaining (PM) Fibers
• Measures PER Up to 40 dB at Peak Wavelength
• Three Wavelength Ranges Cover from 400 nm - 2500 nm:
  • 400 nm - 700 nm (Item # ERM210)
  • 600 nm - 1600 nm (Item # ERM200)
  • 1200 nm - 2500 nm (Item # ERM220)
• Control Via Front Panel Display or USB Interface
• Exchangeable Fiber Connector Adapters Sold Separately
• Supported Connectors: Wide- and Narrow-Key FC/PC, Wide- and Narrow-Key FC/APC, LC/PC, and SC/PC

Common Applications

• Optimized Coupling of Linearly Polarized Light into PM Fibers
• Alignment to Connector Key
• Pigtailing (Alignment of Laser Diodes to PM Fibers)
• Active Alignment for PM Fiber Splicing

The ERM2xx Extinction Ratio Meters measure the polarization extinction ratio (PER) and the polarization angle of polarization-maintaining (PM) fibers. These easy-to-use benchtop devices are useful in alignment applications such as connectorization of PM fibers or pigtailing of laser diodes with PM fibers. A rotating polarizer in conjunction with a photodiode for light detection provides fast and accurate measurements of the PER of PM fibers. Additionally, the polarization angle and the power of the input light beam is measured. Three units are available covering wavelengths from 400 nm to 2500 nm: 400 nm - 700 nm (Item # ERM210), 600 nm - 1600 nm (Item # ERM200), and 1200 nm - 2500 nm (Item # ERM220). For active alignment of PM Fibers, the ERM2xx devices have a Monitor Output with 0.1 V/dB conversion factor, which is compatible with our Vytran^® PM Fusion Splicers.

Connector Accessories
The front panel features a port that accepts exchangeable fiber connector adapters (sold separately). This enables the extinction ratio meters to measure fibers in FC/PC, FC/APC, LC/PC, and SC/PC connectors. To discuss custom connector options not available below, please contact Tech Sales. Thorlabs' ERM2xx Extinction Ratio Meters are shipped with an aperture lock on the fiber connector port to prevent damage during transport. Further details on the shipping lock can be found in the manual.

Module Control
The ERM2xx devices can be controlled via the display and control knob on the front panel. The back of the extinction ratio meter includes a power inlet with a fuse compartment, a banana jack for use with a ground pin, and a BNC for monitor output. See the Front & Back Panel tab for details. The ERM2xx series can also be controlled remotely using our optical power monitor software. The features of the PC control software are highlighted in the Software tab.

All technical data are valid at 23 ± 5 °C and 45 ± 15% relative humidity (non-condensing).

Item #	ERM210	ERM200	ERM220
Wavelength Range	400 nm - 700 nm	600 nm - 1600 nm	1200 nm - 2500 nm
Peak Wavelength	700 nm	1550 nm	2300 nm
Maximum Input Powera	+13 dBm	+13 dBm	+8 dBm
PER Resolution	0.1 dB (Display) 0.01 dB (USB)
PER Rangea	0 to 40 dB (for +13 dBm to -12 dBm) 0 to 30 dB (for -12 dBm to -27 dBm) 0 to 20 dB (for -27 dBm to -37 dBm)	0 to 40 dB (for +13 dBm to -12 dBm) 0 to 30 dB (for -12 dBm to -27 dBm) 0 to 20 dB (for -27 dBm to -37 dBm)	0 to 40 dB (for +8 dBm to -12 dBm) 0 to 30 dB (for -12 dBm to -27 dBm) 0 to 20 dB (for -27 dBm to -37 dBm)
PER Accuracy	<0.5 dB
Polarization Angular Resolution	0.1° (Display) 0.01° (USB)
Accuracy of Polarization Angle	<0.5°
Measuring Speed	Approximately 10 Hz
Responsivity (Click for Graph)	Raw Data	Raw Data	Raw Data
Connector Type	M12 x 0.5 Thread for: ERM2F (Wide-Key, 2.2 mm FC/PC) ERM2F2 (Narrow-Key, 2.0 mm FC/PC) ERM2A (Wide-Key, 2.2 mm FC/APC) ERM2A2 (Narrow-Key, 2.0 mm FC/APC) ERM2L (LC/PC) ERM2S (SC/PC)
Monitor Output
Voltage Output	0 V to 5 V (High-Z, Conversion Factor 0.1 V/dB)
Accuracy	±10 mV (Typ.) ±50 mV (Max)
General
Interface	USB Type B
Display	2.42" OLED
AC Input	Universal, 110 V to 220 V, 50/60 Hz
Power On Warm-Up Time	15 minutes
Operating Temperature Rangeb	5 °C to 40 °C
Storage Temperature Range	-20 °C to 40 °C
Relative Humidity	Max 80% up to 31 °C, Decreasing to 50% at 40 °C
Dimensions (W x H x D)	153.2 mm x 85.4 mm x 188.8 mm (6.03" x 3.36" x 7.43")
Weight	1.05 kg

• At Peak Wavelength
• Non-Condensing

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Figure 3.1  Experimental Setup to Align a PM Fiber's Slow Axis with the Transmission Axis of a Polarizer

Light Source Considerations

For common applications using the ERM2xx, Thorlabs recommends the use of a broadband light source such as Amplified Spontaneous Emission (ASE) or Superluminescent Diodes (SLD) rather than a narrowband source to simplify the alignment procedure. Narrowband sources can be used with additional steps. For more details, see the manual.

Example: Aligning a PM Fiber Patch Cable to a Polarizer's Transmission Axis

A PM fiber patch cable can be aligned to the transmission axis of a polarizer using one of the ERM2xx Extinction Ratio Meters, an SLD, and a FiberBench equipped with a polarizer and a FiberPort by following the procedure below:

1. Connect the output connector of the fiber under test to the fiber adapter on the ERM2xx unit and turn on power.
2. Connect the SLD to the input of the FiberBench with the polarizer.* This will produce polarized light at the output of the FiberBench to which the PM patch cable will be aligned.
3. Connect the input of the PM fiber into the output of the FiberBench.
4. Navigate through the menu items until the ER value is shown on the digital display. Consult the manual for details.
5. Rotate the input of the PM fiber relative to the polarizer's transmission axis mounted in the FiberBench until a maximum ER value is displayed. At the point of maximum ER, the slow axis of the fiber patch cable is aligned with the transmission axis of the polarizer in the FiberBench.

*The coupling optics required are dependent on the light source and are not illustrated here.

Item #s ERM200, ERM210, and ERM220 include the following:

• Extinction Ratio Meter
• USB 2.0 Cable Type A-B, 2 m
• Region-Specific Power Cord
• Test Report
• Quick Reference Manual

The ERM2xx Series Extinction Ratio Meters can be remotely controlled with the OPM software or the ERM200 Series Driver Package, which features drivers for third-party development and is included with the OPM software package.

Compatible Power Meters

• Consoles:
  • PM100A Analog Power and Energy Meter Console
  • PM100D Digital Power and Energy Meter Console
  • PM400 Capacitive Touchscreen Power and Energy Meter Console
  • PM5020 Dual-Channel Benchtop Optical Power and Energy Meter Console (Version 4.0 or Later)
• Complete Power Meters:
  • PM160, PM160T, and PM160T-HP Wireless Handheld Power Meters with Bluetooth^® Technology
  • PM16 Series Compact USB Power Meters
  • PM60 and PM61 Fiber Optic Power Meter Series (Version 6.0 or Later)
•  Interfaces:
  • PM101 Series Power Meter Interfaces with External Readout (Version 2.0 or Later)
  • PM102 Series Power Meter Interfaces with External Readout (Version 2.1 or Later)
  • PM103 Series Power Meter Interfaces with External Readout (Version 3.0 or Later)
  • PM100USB USB Interface Digital Power and Energy Meter

Compatible Extinction Ratio Meters

• ERM2xx Series Extinction Ratio Meters

Optical Power Monitor

The Optical Power Monitor GUI software features power measurement, readout from up to eight power meters, and remote wireless operation.

For details on specific software features, please see the user manual.

Users interested in the legacy Power Meter Software can find it by visiting the software page.

The PM101 Series Power Meters are only compatible with version 2.0 or later. The PM102 Series Power Meters are only compatible with version 2.1 or later. The PM103 Series Power and Energy Meters are only compatible with version 3.0 or later. The PM5020 Console is only compatible with version 4.0 or later. The PM60 and PM61 Power Meter Series are only compatible with version 6.0 or later. 

Optical Power Monitor GUI Software for Touchscreen, Handheld, and USB-Interface Power Meters

Features

• Operate up to Eight Power Meters Simultaneously
• Record and Analyze Measurements in Real Time
• Intuitive Analog Display and Graphing Modes
• Configurable Long-Term Data Logging
• Also Supports Position Measurements with Thermal Position & Power Sensors
• Compatible with USB and Bluetooth^® Connections

The Optical Power Monitor software GUI enables seamless control of up to eight power meters that are connected via USB, RS232, or Bluetooth^® wireless technology^a. The latest software, firmware, drivers, and utilities for these power meters can be downloaded here.

Multiple data measurement and analysis functions are integrated into the GUI package. The interface offers a user-friendly design with minimal use of color and low brightness that is ideal use in dark lab environments while wearing laser safety glasses. Measured data can be displayed in real time as a simulated analog needle, digital values, line graph, or bar graph. Continuously logged and short-term measurements can be recorded for data viewing and analysis at a later point. A built-in statistics mode analyzes measured data and continuously updates to reflect new measurements within the pre-determined measurement period. Beam position measurements are also supported when used with our thermal position & power sensors.

The Optical Power Monitor software package installs the GUI, which then can be used to control the touchscreen, handheld, or USB-interface power meters. Firmware updates for supported power meters are also available. Programming examples and drivers for interfacing with our power and energy meter consoles using LabVIEW, C/C++, Visual C#, and Python are installed with the software; refer to the manual for details.

Please note that the Optical Power Monitor Software uses different drivers than the Power Meter Utilities Software and Thorlabs recommends using the new driver TLPM.dll. For users who wish to use the legacy Power Meter Software or use custom software designed using the older PM100D.dll driver, a Power Meter Driver Switcher program is included for easy swapping of the installed driver between the two versions.

a. The PM61 Series, PM160, PM160T, and PM160T-HP power meters are equipped with Bluetooth^® connections.

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Figure 149A  Power Measurement Mode
Set up and configure up to eight power meters.

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Figure 149B  Power Tuning Mode
Simulated analog needle and digital measurement value provided. Delta Mode, enabled here, shows the fluctuation range during the measurement period.

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Figure 149C  Power Statistics Mode
Calculate numerical statistics for a pre-determined measurement period. The panel displays the analyzed values in a bar graph and the results as numerical values.

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Figure 149D  Position Tuning Mode
Tuning mode can be used with a thermal position & power sensor to aid in beam alignment.

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Figure 149E  Position Statistics Mode
Statistics mode also provides aggregate information for thermal position & power sensors.

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Figure 149F  Data Logging
Enable long-term measurement and simultaneous recording from up to eight power meters. Save data as .csv files for later processing while measurement results are displayed in a graph in real time.