The Mauna Kea Observatories Near‐Infrared Filter Set. I. Defining Optimal 1–5 Micron Bandpasses

A new Mauna Kea Observatories near‐infrared (MKO‐NIR) filter set is described, including techniques and considerations given to designing a new set of bandpasses that are useful at both mid‐ and high‐altitude sites. These filters offer improved photometric linearity and in many cases reduced background, as well as preserving good throughput within the JHKLM atmospheric windows. MKO‐NIR filters have already been deployed within a number of instruments around the world as part of a filter consortium purchase to reduce the unit cost of filters. Through this effort we hope to establish, for the first time, a single standard set of infrared filters at as many observatories as possible.