Compact, power-efficient stacked broadband optical emitters
The present disclosure describes broadband optical emission sources that include a stack of semiconductor layers, wherein each of the semiconductor layers is operable to emit light of a different respective wavelength; a light source operable to provide optical pumping for stimulated photon emission from the stack; wherein the semiconductor layers are disposed sequentially in the stack such that a first one of the semiconductor layers is closest to the light source and a last one of the semiconductor layers is furthest from the light source, and wherein each particular one of the semiconductor layers is at least partially transparent to the light generated by the other semiconductor layers that are closer to the light source than the particular semiconductor layer. The disclosure also describes various spectrometers that include a broadband optical emission device, and optionally include a tuneable wavelength filter operable to allow a selected pass through.
1. A spectrometer comprising:
a broadband optical emission device including a light source operable to be driven so as to generate stimulated optical emission from the broadband optical emission device;
a tunable wavelength filter operable to allow a selected wavelength or range of wavelengths of light from the broadband optical emission device to be incident on a sample, wherein other non-selected wavelengths or ranges of wavelengths of light are reflected back by the tunable wavelength filter toward the broadband optical emission device to generate further stimulated optical emission; and
a light detector operable to sense optical signals based on a portion of the light that passes through the sample or is reflected by the sample.
2. The spectrometer of claim 1 , wherein the tunable wavelength filter comprises a Fabry Perrot filter.
3. The spectrometer of claim 1 wherein the filter comprises a scanning MEMS filter.
4. The spectrometer of claim 1 wherein the filter comprises a linear variable Fabry Perrot filter.