Broadband SLD based source for retina investigations

Two and three SLD diodes are grouped together in order to obtain a compounded source of wide band for OCT investigations. One SLD has a two-lobe spectrum around 840 nm and a compounded spectrum is achieved by using SLDs of smaller wavelengths. This has two advantages: (1) the smaller the wavelength the lower the loss of power through the vitreous due to water absorption; (2) medium band, standard SLDs if used bring a more significant reduction to the coherence length than their counterparts, of medium band but centered at longer wavelength. We show that it is possible to obtain high resolution OCT images with an inexpensive, compact, and easy to operate source.