Silicon windows, Silicon lenses, Silicon optics
Alkor Technologies produces a wide variety of Silicon Optical Components, including Silicon optical lenses, IR filters, or windows.
Silicon optical lenses are ideal for collimation or focusing applications that utilize monochromatic light. These lenses are available in a range of sizes or focal lengths for a wide variety of application needs.
Silicon IR filters, which are integrated into IR applications such as FTIR spectroscopy, are used to transmit or block a specific range of IR wavelengths.
Silicon mirrors are lighter than copper mirrors and lend themselves to lightweight applications with small to medium power output. Silicon mirrors are generally coated with silver, gold and/or dielectric coatings.
Silicon windows and wedges are available uncoated or with a 3 - 5μm antireflection coating.
Silicon lenses for IR LEDs, Diameter 3mm
Optical grade Silicon is normally specified with a resistivity of 10 to 40 Ohm-cm which is higher than most semiconductor applications. The usual Silicon material, unless otherwise specified is CZ, Czochralski Grade which has a Si-O absorption band at 9μm and so not important if the windows are used in the 3 to 5μm thermal band. Where required FZ, Float Zone material can be supplied which does not have this absorption.
Very high resistivity material can be supplied on special order, particularly for TeraHertz applications.
Silicon is used for windows and lenses in the 2-7µm range, ideal choice for IR LED lenses. The refractive index is near 3.4 throughout the range. Silicon high thermal conductivity and low weight are attractive features in IR or FTIR applications. Silicon is also used as a high reflectivity mirror for lasers and for IR silicon viewports.
3-5µm AR/AR Coated Silicon window
Different types of Silicon are available:
Optical grade Silicon - index of refraction