A swept source OCT encodes the optical frequency in time with a spectrally scanning source. So DBR lasers tend to be more spectrally stable than Fabry-Perot lasers with broadband coatings. Indoor thermal radiation can also be a disadvantage with spectrally selective (low-e, low-emissivity) glazing. D'yakonov suggested spectrally equivalent preconditioning and derived non-asymptotic convergence rate bounds. Modulation is chosen to be more spectrally efficient (more bits per OFDM/SOFDMA symbol). One species may have six different opsin genes, but only express one spectrally distinct photoreceptor. Many in-service colored signal flares and spectrally balanced decoy flares contain perchlorate oxidizers. When bound to DNA, it is very similar spectrally to fluorescein. The dark type of rock has a dark matrix with small, bright, spectrally different inclusions. This scheme attempts to make the interference-plus-noise term spectrally white. He also claimed that witches appear spectrally as themselves. MLSs are spectrally flat, with the exception of a near-zero DC term.