For simple applications such as laser diode collimation, or coupling to optical fibers, compact aspheric lenses offer the same magnification and on-axis performance as microscope objectives in a lighter and more compact package. 

In applications that require large acceptance angles, such as light gathering for illumination, spherical lenses are unsuitable due to spherical aberration, or the effect of refractive power of a spherical surface becoming greater with increasing aperture. Aspheric lenses maintain constant focal length or very high NA, avoiding the need for multiple elements to correct spherical aberration. This simplifies system design by reducing weight and component count. It also results in less transmission loss, and less ghosting due to having fewer surfaces. The primary drawback of aspheric lenses is off-axis performance is poor. This is not a problem for coupling to and from optical fibers or collimating light sources, but aspheric lenses are not usable over a wide field of view.

A good way to select the correct aspheric lens for your beam collimation (or focusing) application is to start by finding the appropriate focal length using this formula: f = D( πω/4λ) where f is the lens focal length, D is the 1/e² diameter of the collimated beam, ω is the beam diameter at the focus, and λ is the wavelength.

If you are collimating light, you must then find a aspheric lens with Numeric Aperture larger than that of your fiber or diode in order to capture all the available light. If you are focusing into a fiber, be sure that the NA of the focused beam is smaller than the NA of the multimode fiber to maximize coupling efficiency (this may alternatively be done by using less than the full aperture on a higher NA lens). This analysis will give you a good estimate, but you may find that you need to try a few lenses to get optimum focusing.

With Asphere Adapter, these Compact Aspheric Objective Lenses can mount to our 1 in. mounts which use a clamping screw for securing, for example Double-Bore Mount or Fiber Coupling Kit.

The RMS Threaded Asphere Adapter allows the Compact Aspheric Objective Lenses to be mounted to any RMS threaded optic mounts, for example, Optic Positioner, Microscope Objective Mount, or LT10 1.0 in. Lens Tube with adapter.

The Asphere Adapter is designed to mount any Compact Aspheric Lenses to the Compact Three-axis Lens Positioner.