AMS Technologies carries a broad range of fiber polarization controllers, ranging from component-style fixed polarizers and manually operated mechanical polarization controllers to electrically driven inline polarization controlling devices and polarization switches, to module-style polarization controllers and scramblers, all the way to benchtop instruments for controlling, stabilizing, analyzing and scrambling the polarization of light in optical fibers.
Component-style Fixed Polarizers
Our component-style polarization controllers include a series of fiber optic polarizers in various formats, consisting of input and output collimators with a plate polarizer in between. These broadband polarizers maintain the power extinction ratio for up to several hundreds of nm. An additional series of in-line polarizers is available that offers low insertion loss, high extinction ratio, high return loss and excellent environmental stability and reliability.
The polarization maintaining fiber-to-fiber Faraday rotators contain micro optic components that provide a rotation angle of 45°, while the Faraday mirrors are passive thin film devices that rotate the polarization of the input light by 90° when reflecting it back into the fiber pigtail.
Manually Operated Fiber Polarization Controllers
Manually operated fiber polarization controllers that allow to convert any input polarization to any desired output polarization are available in three versions – in-line controllers that can be inserted into the customer’s existing single mode fiber (also in miniature size for applications where space is critical), pigtailed versions with any size of cable or fiber and your choice of connectors, and finally receptacle-style controllers, using a short section of fiber terminated with your choice of female receptacles.
A series of polarization rotators, controllers and analyzers consists of an input with fiber pigtail or connector receptacle, from one to three polarization optic components (bulk full-, half- and quarter-wave plates and polarizing glass) to accomplish the polarization control, and an output coupler with fiber pigtail or connector receptacle.
PCB-Mountable Miniature Fiber Polarization Controller Modules
Very compact fiber polarization controllers that are designed to be mounted on a PCB are available with three and four channels, based on piezo technology. If switching the polarization between two fixed values is what you need, the PCB-mountable miniature fiber polarization switch may be the right solution for your application.
Fiber Polarization Controller Submodules in PCB Format
The fiber polarization controller submodules in PCB format without packaging and power supply are particularly well suited for integration into OEM sensor or measurement systems. The product range includes a polarization controller module that integrates the miniature three- or four-channel all-fiber dynamic polarization controller with a miniature piezo driver card, so that the state of polarization (SOP) can be directly controlled by an analog or digital signal.
A high-speed polarization state generator (PSG) module generates six states of polarization (-45°, 0°, 45°, 90°, RHC & LHC) across the Poincaré sphere in less than 250 μs, with a repeatability of less than 0.1 degrees. The all-fiber design polarization scrambler module randomizes polarization states and is designed to be easily plugged into existing sensor or measurement equipment. For high-speed polarization characterization, our in-line polarimeter outputs four voltage signals for calculating in microseconds both the degree of polarization (DOP) and the state of polarization (SOP) of the light passing through the device.
Stand-alone Fiber Polarization Controller Modules
Available with either three or four channels, electrically driven polarization controller or scrambler modules employ a novel mechanical fiber squeezing technique to efficiently manipulate the state of polarization within a single mode (SM) fiber in a robust, easy to operate package.
A miniature polarization scrambler module effectively randomizes polarization states and is specially designed for integration into sensor and communication systems that need to work in extreme environmental conditions. Micro-size fiber polarization devices include 3-axis controllers or scramblers in a 2 cubic inch module, requiring only ±12 VDC power supplies.
The product range also includes a polarization tracker module that automatically adjusts the state of polarization (SOP) towards a reference SOP, counteracting continuous input SOP variations as fast as 0.9 ms, as well as a depolarizer module that depolarizes laser output – ideal for minimizing the polarization sensitivity of fiber optic sensor systems.
Benchtop-format Fiber Polarization Controller Instruments
Three different benchtop-format multifunction polarization controllers combine the miniature three- or four-channel all-fiber dynamic polarization controller with proprietary polarization control algorithms to achieve a wide range of polarization control functionalities like discrete, triangle, Rayleigh or tornado scrambling. While the entry version allows for tornado scrambling with up to 12.5 krad/s, the two high-speed polarization controllers provide tornado scrambling with more than 360 krad/s or even up to 11 Mrad/s.
Benchtop-format polarization stabilizers maintain stable output states of polarization (SOP) against rapid input SOP fluctuations in fiber systems and can also be used to suppress noise figure in optical amplifiers, reduce PDL effects, demultiplex polarization division multiplexed channels and eliminate polarization fading in coherent communication and fiber sensor systems. The deterministic polarization synthesizer/analyzer generates and maintains any state of polarization (SOP), regardless of the input SOP.
The polarization scrambler instrument effectively randomizes polarization states with low insertion loss and reflection as well as minimal phase and amplitude modulation. The instrument can be used in automatic test systems under remote control through digital interface options. A dedicated multi mode (MM) scrambler instrument has been specially designed to suppress speckle patterns from a MM fiber that can cause problems in many applications that require uniform, stable light distributions at the fiber output.
Beyond isolators, further fiber components are available like light to fiber couplers/collimators, fiber connectors, mating sleeves and adapters, fiber receptacle collimators and focusers, fiber WDMs, combiners, splitters and couplers, fiber amplifiers, attenuators and isolators, as well as fiber optic circulators, delay lines, filters, switches and other fiber optic assemblies.
Our portfolio of precision optics includes optical lenses, optics assemblies, optical filters, optical prisms, optical mirrors, optical beamsplitters, etalons, optical gratings, optical isolators and polarization optics as well as optical scanners and deflectors or optical modulators, q-switches and pockels cells.
For mounting, adjusting and moving our optical components with high precision, we carry an array of optomechanics and motion control such as optical mounts, rotary and translation stages plus motion controllers as well as optical tables, breadboards and platforms.
Polarization controllers are optical devices that can be used to modify the polarization state of light. For example, component-style fiber optic polarizers allow linearly polarised light to pass while blocking the perpendicularly polarised components of a non-polarised or randomly polarised light source with a high extinction ratio.
Fiber optic Faraday rotators allow the polarization to be rotated by a fixed amount, usually 45°. In a Faraday mirror, the light passes through the Faraday rotator twice, once on the way towards the mirror and once after the reflection on the way back into the fiber. In the process, the polarization of the light is rotated by a total of 90°. Faraday mirrors are suitable for use in systems such as EDFAs, fiber sensors or tunable fiber lasers. As the light passes through the fiber twice with orthogonal polarization, polarization effects due to mechanical or thermal influences on the fiber are minimised.
Most fiber optic polarization controllers change the polarization of the by applying controlled stress to the fiber – for example, by compressing a certain length of fiber with variable pressure. The pressure on the fiber causes refraction in the fiber core, and the fiber behaves like a fractional wave plate. The difference in the time delay of the slow and fast polarization components changes with the amount of pressure applied. Twisting the compressed fiber part against its fixed ends allows different polarization states to be realised.
Mechanical, manually operated polarizers consist of a fiber clamp with manually adjustable clamping pressure, which can also be rotated. With this simple and fast process, any desired output polarization can be achieved. Versions with multiple pressure sections arranged in series usually work with a fixed angle but variable contact pressure per section. These devices can also be equipped with piezo-transducers, allowing electronic control of the polarization.
If the electronic actuators of a polarization controller are controlled with different frequencies or random signals, the controller behaves like a polarization scrambler. As a special form of polarization controller, such a polarization scrambler or depolarizer converts a fixed, known polarization into an arbitrary polarization. This is done by rapidly changing the polarization so that it takes on a random character over time. Polarization scrambling is used, for example, in scientific experiments to eliminate errors caused by polarization effects or to prevent power fluctuations in optical amplifiers by polarization-dependent gain.
Polarization scramblers vary the Stokes vector of the polarization state over the entire Poincaré sphere - with commercially available devices, this can be done at speeds of up to several Mrad/s, and different velocity distributions such as discrete, triangle, quasi-Rayleigh or tornado scrambling can be achieved.
Alternative Terms: Fiber Optic Polarizer; In-line Polarizer; Fiber Faraday Rotator; Fiber Polarization Rotator; Faraday Mirror; Fiber Polarization Switch; Fiber Polarization Controller Module; Polarization State Generator; Fiber Polarization Synthesizer; Fiber Polarization Analyzer; Fiber Polarization Tracker; Fiber Polarization Scrambler; Fiber Depolarizer