Rastered, uniformly separated wavelengths emitted from a two-dimensional vertical-cavity surface-emitting laser array

We report the first two-dimensional vertical-cavity surface-emitting laser (VCSEL) array with each laser emitting a unique, nonredundant wavelength. This was achieved by implementing spatially chirped layers in the VCSEL structure and obliquely aligning the array axes to the direction of the thickness chirp. We obtained 77 wavelengths from a 7×11 VCSEL array with all the lasers emitting single mode. Uniform wavelength separation between neighboring lasers is achieved with the direction of increasing wavelength rastering through the array. All the lasers exhibit nearly the same optical and electrical properties, in spite of the intentionally implemented difference in the emission wavelengths.