As devices that employ photonics components shrink, optical engineers increasingly are turning to the smallest tools at their disposal, and when it comes to lenses, they face a bevy of choices. One recent trend is toward collections of tiny lenses called microlens arrays, which are suited for a variety of tasks from fine tuning laser beams to heightening image quality. These clusters of optics are made up of diffractive, refractive or holographic optical elements with apertures that are generally under 1 mm, although some companies make them as large as 500 mm. The choices among the arrays themselves are numerous, and system designers must weigh the benefits of each technology so they can reap the rewards of integrating them into their photonic products.