Silicon polarising beamsplitter cubes

Precision optical solutions company Reo has introduced its range of silicon polarising beamsplitter cubes for operation in the mid-infrared spectral range.

In particular, these optics offer a mix of broad bandwidth (2-6µm) operation, high laser damage threshold, high transmission (>95 per cent) and high extinction ratio (>100,000:1). The extinction ratio can be extended to greater than 1,000,000:1 over narrower spectral ranges. These polarising beamsplitter cubes are available anywhere in the 1mm to 75mm size range. Laser damage threshold for these devices is limited only by the bulk material, and is typically in the 1.5J/cm2 range, (for a 75ns pulse at 2.05µm). This high laser damage threshold level is achieved through the use of ion beam sputtered coatings, together with assemblies based on REO’s proprietary Activated Covalent Bonding technology.