Product type:
B membrane Φ6 f15 Ravg<0.5% @650-1100nm;
B membrane Φ6 f10 Ravg<0.5% @650-1100nm;
B membrane Φ6 f12 Ravg<0.5% @650-1100nm;
B membrane Φ6 f30 Ravg<0.5% @650-1100nm;

Product Introduction:
    Material: N-BK7;
    Wavelength range: can choose from uncoated or one of three types of broadband, with excellent transmittance from visible light to near-infrared wavelength range, and focal length from 10-1000mm;

Overview:
These uncoated flat convex lenses are produced using RoHS compliant BK7 (N-BK7). N-BK7 may be the most commonly used optical glass for producing high-quality optical components. When the additional advantages of ultraviolet fused silica are not needed (high transmittance and low coefficient of thermal expansion up to the UV band), N-BK7 glass is generally selected.

Application:
Like all planar convex lenses, these lenses have a positive focal length and are close to optimal shape lenses suitable for applications with infinite and finite conjugate ratios. They can focus a collimated beam or collimate a point light source. In order to minimize spherical aberration, the collimated beam should be incident on the surface of the lens during focusing, and the point light source should be incident on the plane of the lens during collimation.
Optical lens:
Spherical single lens
    Spherical single lenses are a good choice for many applications where aberration is not very important, as they are simple and inexpensive lens types. For simple applications, standard flat convex lenses, flat concave lenses, biconvex lenses, and biconvex lenses are sufficient. To achieve better performance, the external lens has been optimized to reduce aberration while still maintaining a spherical surface. Using multiple lens elements within a composite optical system can achieve more performance improvements. These multi element optical systems typically utilize crescent shaped lenses, although they are rarely used alone. For demanding applications, the performance of spherical single lenses will not be as good as that of achromatic lenses (for both broadband and monochromatic light sources) or spherical lenses (for monochromatic light sources). For more details on other types of lenses, please refer to the labels for achromatic and aspheric lenses.
Standard single lens
    Multiple basic single lens designs: planar convex lens, biconvex lens, planar concave lens, and biconvex lens. Each of these lenses is suitable for different applications. Convex and biconvex lenses are positive lenses (i.e., they have a positive focal length) that focus collimated light to a focal point, while concave and biconvex lenses are negative lenses that can cause collimated light to diverge. The shape of each single lens minimizes aberration based on a certain conjugate ratio, which is defined as the ratio of object distance to image distance (referred to as conjugate distance).

Positive lens:
Planoconvex lens
    A planar convex lens is suitable for situations where one conjugate distance is more than five times that of another conjugate distance. The performance of this lens shape is suitable for situations with infinite conjugation ratio (focusing collimation light or point light source collimation).
Biconvex lens
    A biconvex lens is suitable for situations where one conjugate distance is 0.2 to 5 times the conjugate distance of another. The performance of this lens shape is suitable for situations where the object distance and image distance are the same.

Negative lens:
Flat concave lens
    Flat concave lenses are suitable for situations where one conjugate distance is more than five times that of another conjugate distance. They introduce negative spherical aberrations and can be used to balance the spherical aberrations introduced by a single lens with positive focal length.
Biconcave lens
    Double concave lenses have a negative focal length and are typically used to increase the divergence of aggregated light.
Aberration reduction
    In order to minimize spherical aberration, the lens should be placed with the side with greater curvature facing further towards the common major point. For flat convex and flat concave lenses used in infinite co ratio, this means that the surface should face the collimated beam (as shown in the above figure). The number of lenses is defined as the focal length divided by the aperture diameter, which has a significant impact on the degree of aberration. A smaller lens ("fast" lens) introduces significantly more aberrations than a larger lens ("slow" lens). The shape of the lens becomes very important when it is below about f/10 and should be considered as a substitute for spherical single lenses and other lenses below about f/2 (such as achromatic lenses and aspherical lenses).
Appearance lens
    The shape lens is designed to minimize spherical and coma aberrations (caused by light not on the optical axis), while still utilizing the spherical surface to form the lens. Utilizing a spherical design makes it easier to manufacture external lenses than aspherical lenses (as described on the aspherical lens label), reducing costs. Each side of the external lens is polished to have different curvature radii, providing better performance for spherical single lenses. For small diameter input beams, the external lens even has diffraction performance. These lenses are typically used in high-power applications where achromatic glued lenses cannot be used.
Curved Moon Lens and Multi Element Lens System
    Moonlight lenses are typically used in multi element optical systems to modify the focal length without introducing significant spherical aberrations. The optical performance of a multi element lens system is usually significantly better than that of a single lens. In these systems, the aberration introduced by one element can be corrected by subsequent optical elements. These lenses have a convex and a concave surface, and they can be positive or negative lenses.

Crescent lens
Meniscus lens
    A crescent lens is usually used together with another lens in composite optical assemblies. When used in this structure, a regular meniscus lens will shorten the focal length, increase the numerical aperture (NA) of the system, and will not introduce significant spherical aberrations.
Negative meniscus lens
    Negative meniscus lenses are usually used together with another lens in composite optical assemblies. When used in this structure, the negative meniscus lens increases the focal length and reduces the numerical aperture (NA) of the system.
Achromatic lens
    Achromatic lenses are a good choice for any demanding optical application, as they have substantially better performance than spherical single lenses. Achromatic doublet lenses are sufficient for most applications of infinite conjugation, and doublet lens pairs are an ideal choice for finite conjugation. However, the adhesive used in these optical components reduces their damage threshold and limits their availability in high-power systems. Double lens with air separation is an ideal choice for high-power applications, as their damage threshold is greater than that of achromatic glued lenses. In addition, a double lens with air separation has two more design variables than a double glued lens, as the inner surface of the lens does not need to have the same curvature. These additional variables make the performance of air spaced dual lenses far superior to that of double bonded lenses in terms of transmitted wavefront error, spot size, and aberration. However, air separated dual lenses are also more expensive than double bonded lenses.
    Achromatic triple lenses can be designed for both finite and infinite conjugation ratios. In the middle of these triple lenses is a low refractive index optical element, which is glued between two identical high refractive index external optical elements. They can correct axial and transverse color differences, and their symmetrical design has better performance than glued double lens.
Double glued lens
    Achromatic double glued lenses have more advantages than simple single lenses, including reduced color difference, improved off axis performance, and smaller focal spot. These dual lenses have a positive focal length and are optimized for infinite conjugate ratios.
Air gap double lens
    The performance of air separated dual lens is better than that of double glued lens because their lenses are separate. These optical components are ideal choices for high-power applications because their damage threshold is greater than that of double bonded lenses. These dual lenses have a positive focal length and are optimized for infinite conjugation ratios.
Double lens pair
    Achromatic dual lens pairs have the advantages of achromatic lenses and are optimized for finite conjugation. These lens pairs are ideal choices for image relay and amplification systems.
Achromatic triple lens
    Achromatic triple lenses perform better than achromatic double lenses. An achromatic triple lens is a simple lens that can correct all major color differences. The Steinheil triple lens is optimized for finite conjugation ratio, while the Hastings triple lens is optimized for infinite conjugation ratio.