Our N-BK7 precision plano-convex lenses are polished to tight tolerances using master test plates to ensure minimum wavefront distortion for demanding laser electro-optic focusing applications.
- Low cost, high performance N-BK7 optical glass
- Plano-Convex shape for focusing applications
- ≤ λ/4 surface irregularity, 40-20 scratch-dig
- Broadband or 1064 nm AR coatings
- Standardized focal lengths across different lens sizes
- RoHS Certified
N-BK7 for VIS and NIR Applications
N-BK7 is an excellent lens material for most visible and near infrared applications. It is the most common borosilicate crown optical glass, and it provides great performance at a good value. Its high homogeneity, low bubble and inclusion content, and straightforward manufacturability make it a good choice for transmissive optics.
Plano-Convex Lens Shape for Focusing Light
Plano-Convex lenses are the best choice for focusing parallel rays of light to a single point. They can be used to focus, collect and collimate light. The asymmetry of this lens shape minimizes spherical aberration in situations where the object and image are located at unequal distance from the lens. The optimum case is where the object is placed at infinity with parallel rays entering lens and the final image is a focused point.
High Quality Precision Lens Surfaces
Our precision plano-convex lenses are polished to tight tolerances minimizing wavefront distortion. Tight surface quality tolerances minimize scatter and unwanted diffraction effects. These lenses have a 40-20 scratch-dig surface quality, and a 1.5 λ surface power accuracy.
Broadband Visible Antireflection Coatings
Our single layer Magnesium Fluoride AR coating is a common choice that offers an extremely broad visible wavelength range at a reasonable price. Compared to the uncoated surface, the MgF2 coating provides a significant improvement by reducing the reflectance to less than 1.5%. It works extremely well from 400-700 nm and at angles of incidence less than 15 degrees. Our AR.14 broadband multilayer antireflection coating markedly improves the transmission efficiency of these lenses by reducing surface reflections over a 430-700 nm wavelength range. This AR coating performs effectively for multiple visible wavelengths and tunable lasers eliminating the need for several sets of optics.
Broadband Multilayer IR Antireflection Coatings
We offer two multilayer AR coatings options for IR and NIR applications. Our AR.16 coating is recommended for NIR applications in the 650-1000 nm range. Our AR.18 coating is for IR applications in the 1000-1550 nm range.
1064 nm Laser Line Antireflection V-Coating
Our AR.33 laser line V-coating offers the lowest reflectance at 1064 nm for maximum transmission while maintaining high durability and high damage resistance. Valuable laser energy is efficiently transmitted through the plano-convex lens rather than lost to surface reflection and scattering. The trade off to its superior performance is the minimal laser line wavelength range.
Standardized Focal Lengths
Standard effective focal lengths provide a systematic approach allowing for lenses of different sizes to be interchanged without requiring other changes to your optical system.
These lenses have been tested for dangerous substances like Pb, Cd, Hg, Hex-Cr, PBB, and PBDE and have been found to be in compliance with RoHS allowable levels.