Speckle-free laser imaging using random laser illumination

• Published in: Nature photonics Vol. 6; no. 6; pp. 355 - 359
• Main Authors: Redding, Brandon, Choma, Michael A., Cao, Hui
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 2012; Nature Publishing Group
• Subjects: 639/624/1020; 639/624/1107/510; Applied and Technical Physics; Artefacts; Coherence; Illumination; Imaging; Lasers; letter; Light sources; Microscopy; Physics; Physics and Astronomy; Quantum Physics; Superluminescent diodes
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/nphoton.2012.90

Many imaging applications require increasingly bright illumination sources, motivating the replacement of conventional thermal light sources with bright light-emitting diodes, superluminescent diodes and lasers. Despite their brightness, lasers and superluminescent diodes are poorly suited for full-field imaging applications because their high spatial coherence leads to coherent artefacts such as speckle that corrupt image formation
1
,
2
. We recently demonstrated that random lasers can be engineered to provide low spatial coherence
3
. Here, we exploit the low spatial coherence of specifically designed random lasers to demonstrate speckle-free full-field imaging in the setting of intense optical scattering. We quantitatively show that images generated with random laser illumination exhibit superior quality than images generated with spatially coherent illumination. By providing intense laser illumination without the drawback of coherent artefacts, random lasers are well suited for a host of full-field imaging applications from full-field microscopy
4
to digital light projector systems
5
.
Exploiting the low spatial coherence of specifically designed random lasers, researchers demonstrate speckle-free full-field imaging in the regime of intense optical scattering. Their results show that the quality of images generated from random-laser illumination is superior to those generated from spatially coherent illumination.