We supply liquid crystal based Fast Polarisation Modulator (FPM) and Variable Polarisation Rotator (VPR) devices from LC-Tec. The FPM and VPR series are a range of liquid crystal (LC)-based optical components which control light polarisation by an externally applied drive voltage.
Compared to conventional modulators/rotators, electro-optical LC modulators/rotators contain no moving parts, are completely vibration-free, and have a small footprint.
Most modulator/rotator models consist of a polarisation modulator in form of a LC cell together with a polariser. Applying the drive voltage reorients the birefringent LC molecules, changing the phase retardation of light passing through the LC cell. This results in a change in polarisation of light passing through the full modulator/rotator structure. Some models employ two LC cells for achieving enhanced performance.
In order to meet a wide range of requirements for various applications, a series of FPM and VPR models possessing different electro-optical properties are offered in a number of standard sizes, all available with short lead times.
FPM(L): Offers high contrast between two orthogonal linear polarisation output states even at moderate drive voltage amplitude together with fast switching from polarisation altering to non-altering state. It is suitable for customers seeking a general purpose modulator without having extreme requirements for fast switching.
FPM(L)-NIR(1100): Provides near infrared operation and is design for optimum performance around 1,100nm. Custom designing for wavelengths up to 2,000nm is possible.
X-FPM(L): The fastest single-cell modulator which differs from the FPM(L) model by extra-fast switching speeds, both response and relaxation. This modulator should be considered for applications in which high-frequency operation between two linear polarisation states is desired.
X-FPM(4L): Incorporates a dual-cell structure in order to achieve switching between 4 linear polarisation states, oriented at -45°, 0°, +45°, and +90°, respectively. It is especially suitable for polarisation imaging applications.
PolarSpeed®-M(L): Based on LC-Tec’s patented PolarSpeed® technology, this dual-cell modulator offers unprecedented 30µs symmetrical switching times in both directions. The PolarSpeed® modulator is especially suitable for demanding high frame rate applications, such as time-multiplexed stereoscopic 3D, and is compatible with up to 540 FPS operation.
VPR (Variable Polarization Rotator)
The VPR differs from all other polarization modulator models by offering continuous analogue rotation of linear polarisation output states between 0° and 180°.
For customers not finding their required modulator/rotator properties further optimisation and custom designing are possible.
Models under development
FPM(L)-LAS (Fast Polarization Modulator – Laser Operation): By optimising both the manufacturing process and material choice, the FPM(L)-LAS is compatible with low-power laser operation without sacrificing product durability or lifetime.
Polarisation output: The modulators/rotators are configured for linear polarisation output states. Switching between other pre-defined polarisation states is also possible, for example between linear and circular polarisation as well as between left- and right-handed circular polarisation.
Entrance polariser: The modulators/rotators are supplied with an input (or exit depending on usage) polariser as standard. For customers having linearly polarised incident light, the modulators/rotators can be supplied without any polariser, 0P is then added to product name.
Variable retarders: If continuous analogue control of the phase retardation is desired, the X-FPM can be offered as a variable retarder (wave plate) with variable retardation from 0 to 2λ.