Luna PSW-003-M High-Speed Polarization Switch Module with TTL Driver Board

Self-latching polarization switch module with integrated driver board, TTL logic control and 45 µs typical SOP switching time.

Operation wavelength, C band: 1520 to 1580 nm (typical 1550 nm)
Operation wavelength, O band: 1280 to 1340 nm (typical 1310 nm)
Insertion loss: 0.5 dB
State dependent loss: 0.05 dB

Datasheet

Overview

The Luna PSW-003-M is a high-speed, self-latching polarization switch module that switches between two output states of polarization (SOPs). Depending on the version, the two output states are 45° or 90° apart, or the device works as a linear-to-circular converter.

The module combines the PSW-003 polarization switch with a compact driver board. The user controls the switch state with TTL logic levels, so there is no need to build high-current driver circuits. The driver board uses a MOSFET H-bridge to generate the forward and reverse current pulses that drive the switch. The logic levels on input pins A_IN and B_IN set the drive state. With both pins low (coast), the switch holds its current state. Pulling A_IN or B_IN high for at least 50 µs switches it to the forward or reverse rotation state.

Principle of operation

A linear or elliptical input SOP is rotated by +θ/2 or −θ/2, so the relative angle θ between the two output polarizations is 45° or 90°. Circular input SOPs are not affected by a rotator switch. On the Poincaré sphere, the transformation follows the latitude line on which the input SOP falls. PM-input versions usually have an input polarizer aligned to the slow axis, which keeps the transformation on the equator. Linear-to-circular converter switches usually have a PM input and an SM output. Their positive output state is linear and their negative output state is LCP.

The module runs from a +12 VDC supply and draws a low average current because it uses pulse drive. Typical uses include polarization-sensitive OCT, polarization-sensitive OTDR or OFDR, PMD monitoring, polarization modulation, polarization detection and polarization metrology.

Key Features

Self-latching
Pulse drive with low power dissipation
Control of the switch state with TTL logic levels via integrated driver board
Flexible driving method: quadrature dual-port logic signal
Low power consumption: average current 5.7mA at 1KHz switch frequency, 2.1mA at 1Hz
Power supply +12VDC
Compact: 42(L) x 20.5(W) x 17.5(H) mm
Two output SOPs 45° or 90° apart, or linear-to-circular conversion
Fast switching time 45 μs (typical)
SOP repeatability 0.1°

Specifications

Optical Characteristics

Operation wavelength, C band	1520 to 1580 nm (typical 1550 nm) Wavelength range is center wavelength (λc)±30nm
Operation wavelength, O band	1280 to 1340 nm (typical 1310 nm) Wavelength range is center wavelength (λc)±30nm
Insertion loss	0.5 dB Max; values referenced without connectors
State dependent loss	0.05 dB Max
Wavelength dependent loss	0.1 dB Max
Return loss	-55 dB
SOP repeatability (on Poincaré sphere)	±0.1 deg
SOP rotation angle (center wavelength and 25°C)	45±0.5 or 90±1 deg Web page states 45±0.5° or 90±0.5° at λc, 23°C; datasheet value used
SOP rotation angle (all wavelengths and temperatures)	45 or 90±5 deg Over all wavelengths and temperatures in the operational ranges
Rotation angle wavelength dependence, 45° 1550nm PSW	-0.065 deg/nm Relative angle between output SOPs; negative sign means the angle decreases with increasing wavelength
Rotation angle wavelength dependence, 90° 1550nm PSW	-0.13 deg/nm
Rotation angle wavelength dependence, 45° 1310nm PSW	-0.085 deg/nm
Rotation angle wavelength dependence, 90° 1310nm PSW	-0.17 deg/nm
Rotation angle temperature dependence, 45° PSW	-0.07 deg/°C Negative sign means the angle decreases with increasing temperature
Rotation angle temperature dependence, 90° PSW	-0.14 deg/°C
SOP switching time	40 / 45 / 50 µs Min / typical / max; rise/fall time (t5 – t4), see Figure 8
Optical power handling	300 mW

Electrical Inputs

Power supply voltage	11 / 12 / 15 V Min / typical / max
Logic pin signal pulse width	50 / 80 / 1000 µs Min / typical / max
Signal input resistance (A_IN, B_IN)	50K
Electrical connector on board	Harwin M50-3530442 or equivalent (4-pin, 1.27mm pitch)
Average current at 1KHz switch frequency	5.7mA Power supply +12VDC
Average current at 1Hz switch frequency	2.1mA Power supply +12VDC

Timing Characteristics

SOP switch delay time	20 / 25 µs Min / typical; power supply 12V
SOP switch time	40 / 45 / 50 µs Min / typical / max; power supply 12V

Absolute Maximum Ratings

Optical input power	300 mW Max
Power supply voltage (DC)	11 to 13 V Min / max
Quiescent current	2.0 mA Max
Operating current	45 mA Alternating switching frequency 8KHz
Maximum transient current	160 mA <1µ
Pulse width at power supply voltage 12V	50 to 1000 µs Min / max

Physical and Environmental

Operating temperature	0 to 50 °C
Storage temperature	-40 to 85 °C
Fiber type	SM or PM Rotator switches can have SM or PM pigtails; linear to circular switches typically have PM input and SM output
Operational temperature elevation (worst case)	5 °C Max; measured at room temperature ambient, 12V supply, continuous switching with 50μs pulse width and interval
Dimensions	42(L) x 20.5(W) x 17.5(H) mm

Specifications are taken from the manufacturer's documentation. See the datasheet for complete and current values.

Applications

Polarization sensitive OCT
Polarization sensitive OTDR or OFDR
PMD monitoring
Polarization modulation
Polarization detection
Polarization metrology
Polarization diversified detectors and sensors
Optical device test and characterization
Manufacturing test of fiber optic assemblies
OEM modules for fiber optic sensing

Options & Accessories

Option	Description
15	Wavelength 1550 nm
13	Wavelength 1310 nm
90	SOP rotation 90°
45	SOP rotation 45°
LCL	Linear to LCP — Linear to circular converter
SS	Fiber type SM to SM
PP	Fiber type PM to PM
PS	Fiber type PM to SM
0	No input polarizer — For PM PSW
P	Input polarizer (slow axis) — For PM PSW
1.0	Pigtail length 1.0 m — Other lengths: specify
NC	No connector
FC/APC	FC/APC connector — Other connectors: specify