April 2026 Hot Products
Knight Optical. Read on to find out which products were hot for April and why they might be exactly what you need for your next project. From deep-sea imaging rigs to laser systems and precision scientific instruments, April’s bestsellers reflect the challenges our customers are solving every day. The April hot products cover three different applications, but they share a common thread: the need for optical components that perform reliably when the stakes are high.
Sapphire Windows
Sapphire is an extremely durable material, being the second hardest crystalline material to diamond, and is used in optical components due to its wide transmission range and durability, offering resistance to extreme temperatures, chemical corrosion, and high radiation. Sapphire is naturally birefringent, meaning it has two different refractive indices, and so for critical optical applications and imaging systems, c-cut sapphire is preferred to minimise optical distortion, while random-cut sapphire (grown more easily at a 60° off-axis angle) is suitable for less sensitive applications.
Application Example: Underwater imaging, protective windows for sensors in harsh environments.
Stock Capabilities: Diameters from 5-100mm available. C-cut and random cut sapphire options.
Custom Capabilities: Dimensions to suit customer applications, optical coatings such as antireflective (AR) can be applied.
Cylindrical Lenses
Cylindrical lenses are designed to focus light into a straight line, rather than to a single point, and allow for one dimensional shaping of light along a line. They are often used to change the profile of laser beams, for example to correct for astigmatism and ellipticity in diode lasers or to generate lines from single mode lasers. Knight Optical offers a range of stock and bespoke cylindrical lenses and all can be AR coated for NIR transmission, typically between 450-900nm.
- Stock Capabilities: N-BK7 and UVFS planoconvex and planoconcave cylindrical lens options with focal lengths ranging from 12.5mm to 150mm. Coated options available.
- Custom Capabilities: Different materials, dimensions, and custom coatings.
- Application Example: Underwater imaging, protective windows for sensors in harsh environments.
Interference Bandpass Filters
Thin-film coated optical filters which selectively transmits a precise, narrow waveband of light whilst effectively blocking light outside of the band.
- Stock Capabilities: Narrowband (3nm), standard waveband (10-20nm), and broadband (40-75nm) waveband options. 214nm-2000nm centre wavelength (CWL) options. 12.5mm and 25mm mounted options for all wavebands, and 50mm mounted options for a select few wavelengths.
- Custom Capabilities: Most aspects of these filters can be customised, but each parameter influences the other, so consider bandwith, centre wavelength, peak transmission, and mounting diameter when ordering.
- Application Example: Spectroscopy, automated inspection systems – applications requiring precise wavelength selection.
Knight Optical provide a wide range of both stock and custom optical components through our website to suit your needs. Alternatively, you can reach out to us to discuss a bespoke component if you cannot find what you need.
