Low-threshold multiwavelength VCSEL arrays fabricated by nonplanar MOCVD

A novel approach of on-wafer wavelength control for vertical cavity surface emitting lasers (VCSELs) is proposed using nonplanar metalorganic chemical vapor deposition. The resonant wavelength of 980nm VCSELs grown on a patterned substrate can be controlled in the wavelength range over 45nm by changing the size of circular patterns. We have fabricated linear and 2D multiwavelength vertical surface emitting laser (VCSEL) arrays fabricated by using this technique. The threshold of multi-wavelength VCSELs formed on the patterned substrate is as low as 3 mA. A possibility of an extremely large wavelength span for multi- wavelength arrays will be discussed. The proposed method will be useful for multi-wavelength VCSEL arrays as well as for the cancellation of wavelength nonuniformity across a wafer.