Luna PSW-003 High-Speed Self-Latching Polarization Switch

Solid-state self-latching polarization switch that rotates the SOP by 45° or 90° or converts linear to circular, with 45 µs typical switching time.

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

Datasheet

Overview

The Luna PSW-003 is an all solid-state, self-latching polarization switch that switches between two output states of polarization (SOPs). Depending on the version, it rotates the SOP of incoming light by a fixed angle of 45° or 90°, or converts a linear input polarization state to a left circular output state. Typical switching time is 45 µs.

Principle of operation

The switch is electrically controlled with pulsed drive currents. The output SOP is rotated by +θ/2 or −θ/2 from the input SOP, so that the relative angle θ between the two output polarizations is 45° or 90°. Circular input states are unaffected by a rotator switch. Because the device is self-latching, the output polarization state is maintained after a drive pulse and no current is required to hold the state, giving zero static power dissipation. The manufacturer recommends driving it with a current-limited MOSFET H-bridge and does not recommend DC drive.

Fiber configurations

Input and output pigtails can be single-mode or polarization-maintaining. PM-input devices include an input polarizer aligned to the slow axis, which constrains the light entering the rotator to a known linear state. Linear-to-circular converter switches generally have PM input and SM output pigtails.

The PSW-003 is a small module for OEM integration wherever polarization switching is required. A module version, the PSW-003-M, combines the switch with a driver board controlled by TTL logic levels.

Key Features

Digitally switched SOP
Fast switching time 45 µs (typical)
SOP repeatability 0.1°
Self-latching
Zero static power dissipation
Compact
Minimal heat generation
Fixed 45° or 90° rotation, or linear-to-circular conversion
SM or PM input and output fibers

Specifications

Optical Characteristics

Operation wavelength, C band 15	1520 / 1550 / 1580 nm Min / typical / max; wavelength range is center wavelength (λc) ±30 nm
Operation wavelength, O band 13	1280 / 1310 / 1340 nm Min / typical / max; wavelength range is center wavelength (λc) ±30 nm
Insertion loss	0.5 dB Max; values referenced without connectors
State dependent loss	0.05 dB
Wavelength dependent loss	0.1 dB
Return loss	-55 dB
SOP repeatability (on Poincaré sphere)	±0.1° Web page gives ±0.1°; the datasheet prints the unit as dB
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° 1550 nm PSW 15, 45	-0.065 deg/nm Negative sign: angle decreases with increasing wavelength
Rotation angle wavelength dependence, 90° 1550 nm PSW 15, 90	-0.13 deg/nm
Rotation angle wavelength dependence, 45° 1310 nm PSW 13, 45	-0.085 deg/nm
Rotation angle wavelength dependence, 90° 1310 nm PSW 13, 90	-0.17 deg/nm
Rotation angle temperature dependence, 45° PSW 45	-0.07 deg/°C Same for 1310 and 1550 nm PSWs
Rotation angle temperature dependence, 90° PSW 90	-0.14 deg/°C Same for 1310 and 1550 nm PSWs
Optical power handling	300 mW

Switching and Timing

SOP switching time at bias voltage 10V	40 / 45 / 50 µs Min / typical / max; time from drive pulse leading edge to completion of SOP transition
SOP switching time at bias voltage 5V	70 / 80 / 100 µs Min / typical / max
SOP switching time at bias voltage 3.3V	90 / 120 / 150 µs Min / typical / max
SOP switch delay time at bias 10V	20 / 25 / 30 µs Min / typical / max (t4, t6)
SOP switch delay time at bias 5V	30 / 35 / 40 µs Min / typical / max (t4, t6)
SOP switch delay time at bias 3.3V	40 / 45 / 50 µs Min / typical / max (t4, t6)

Electrical Characteristics (Dynamic)

Drive signal pulse width at bias voltage 10V	50 to 130 µs Min to max pulse width required to switch and latch the SOP
Drive signal pulse width at bias voltage 5V	110 to 550 µs Min to max
Drive signal pulse width at bias voltage 3.3V	170 to 1000 µs Min to max
Peak pulsed drive current at bias voltage 10V	65 to 150 mA Min to max
Peak pulsed drive current at bias voltage 5V	60 to 150 mA Min to max
Peak pulsed drive current at bias voltage 3.3V	55 to 110 mA Min to max
Self-latching current	0 mA No current required to maintain SOP after latching
Equivalent circuit inductance	5mH Ideal inductor in series with DC resistance

Absolute Maximum Ratings

Optical input power	300 mW
Power dissipation	1 W
Peak drive current Ipeak	150 mA Maximum allowed instantaneous current during a drive pulse
Pulse width at bias voltage 10V	130 µs Pulse width at which instantaneous current may reach 150 mA
Pulse width at bias voltage 5V	550 µs
Pulse width at bias voltage 3.3V	1000 µs

Physical and Environmental

Operating temperature	0 to 50 °C
Storage temperature	-40 to 85 °C
Operational temperature elevation (worst case)	5 °C Measured at room temperature with H-bridge driver at 10V bias; drive pulse width and interval both 50 µs
Input fiber	SM or PM
Output fiber	SM or PM
Pigtail length	1.0 m
Connector type	FC/APC

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

Applications

Polarization diversified detectors and sensors
Polarization sensitive OCT
Polarization metrology
Polarization sensitive OTDR and OFDR
PMD monitoring
Polarization modulation
Polarization detection
Fiber optic sensing
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 — Ordering code for wavelength
13	Wavelength 1310 nm — Ordering code for wavelength
90	SOP rotation 90°
45	SOP rotation 45°
LCL	Linear to LCP converter
SS	Fiber type SM to SM
PP	Fiber type PM to PM
PS	Fiber type PM to SM
P	Input polarizer (slow axis) — For PM input
1.0	Pigtail length 1.0 m