液晶相位延遲器

液晶相位延遲器是通過電壓控制液晶分子的折射率來實現對光的相位延遲。能夠精確調控特定波長的相位延遲量。

提供多種規格的產品，分別適用于工業和科研等領域的需要，亦可根據客戶需要定制產品。

The LC Variable Phase Retarder

The liquid crystal variable phase retarder (or phase shifter) is a transmissive element with an electrically tunable optical phase retardance. Optical retardation is often obtained with piezoelectric mirrors. However this option is not ideal if robust and compact design is necessary. This product offer an interesting alternative especially when working with polarized light (which is often the case when working with lasers). The Arcoptix phase shifter is a thin transmissive element causing minimal losses and can be simply placed within the optical path of our system. The more, its optical retardation is electrically tunable with the LC driver of ARCoptix (but it can also be driven with simple labor alternative power supply). It can also be used as optical valve (for a narrow wavelength range) or as polarization State controller. To summarize :

• Compact and robust device      • Transmissive element       • No moving parts       • Electrically Tunable	• Needs polarized light       • Weak absorption in VIS       • Optical valve (with extra polarizer)       • Polarization state controller
10mm aperture Scientific grade LC variable	20mm aperture Scientific grade LC variable phase retarder

The liquid crystal variable phase shifter can be compared to a variable waveplate. By addressing it with the right voltage, it is able to provide any phase shift from zero to several times the light wavelength. They can be used throughout the visible and the near infrared region (400nm to 1800nm) without losses higher than 15%. Thanks to the use of thick substrate (scientific grade) and a special liquid crystal bend were are capable to offer robust equipment with minimal wavefront distortion and power absorption.

Retarder type selection

In functions of your needs you can select essentially between three categories of products:

Principle

The Arcoptix variable phase retarders are manufactured with standard liquid crystal technology. As depicted in figure 1, they are principally made of a liquid crystal layer sandwiched between two flat glass plates coated with a transparent electrode (ITO) and an alignment layer. The two glass plates are precisely spaced apart with a matrix of glass fibers. The cavity formed by these plates is filled with a special blend of liquid crystals optimized for high birefringence, small temperature dependence and high stability. The cell is hermetically sealed with a polymer frame. The alignment layer is a gently rubbed polyimide layer necessary for the alignment of the LC molecules. The electric field that can be induced by applying a voltage on the transparent ITO electrodes (0-7V) modifies the alignment of the LC molecules and by the same way the apparent retardance of the cell. Figure (a) shows the alignment of the LC molecules when no voltage is applied. In this case the molecules are aligned along the glass plates and the retardance (along the optical axis) is maximum. Figure (c) shows the other extreme case where a “high” voltage (7V) is applied and the electric field forces the LC molecules to align perpendicularly to the glass plates (parallel to the electric field). Figure (b) shows an intermediate state where we apply a small voltage of about 3V. In this case the molecules have an oblique orientation and the apparent retardation is somewhere in between the maximum retardation (several times the wavelength) and the minimum retardation (almost zero).

• 徑向偏振轉換器
• 偏振旋轉器