A novel broadband photodetector and its array having spectral response ranging from visible to shortwave infrared (VIS-SWIR) is developed for focal plane array (FPA) for military, security, industrial imaging applications, and optical communications. The photodetector is based on InGaAs and fabricated on InP substrate, exhibiting high sensitivity, high quantum efficiency, and yet cost-effective. In order to realize a small weight, power, and cost effectiveness (SWAP-C) camera and receiver, the photodetector requires having low dark current at high operating temperatures, which saves power for cooling. This paper explains the photodetector structure, design-simulation for optimizing the structural parameters, and performance of the photodetector. An analytical closed form model is derived for design and simulation of the broadband photodetector. Both theoretical and experimental results of electrical and optical characteristics of the photodetectors are also presented in this paper.