Lasers are preferred as light sources in modern microscope imaging technique because of their ability to deliver fast a pulsed and extremely high intensity radiation to a target enabling rapid image acquisition. However traditional Lasers produce images which are blurred and this is caused due to a phenomenon called “high spatial coherence.”
Such speckles can degrade the quality of pictures in wide field microscopy, a technique commonly used to reproduce broad swath images of the whole side of the cell or something more intricate like the inner working of a cell.
The answer to this problem was laser-like light source with “low spatial coherence.” Low spatial coherence means that the electric field does not oscillate in different position like the traditional lasers.
Researchers at Texas A&M University have achieved just that when they demonstrated a newly emerging technique known as random Raman lasing emission can produce a bright, speckle-free, strobe light source with potential application in high-speed wide-field microscopy.
Brett Hokr, a physicist at Texas A&M University who led the research said, “The random Raman laser is unlike any existing laser light source. We found that random Raman lasing emission has a low level of spatial coherence. The emission can be used to produce a wide-field speckle-free quality image with a strobe time on the order of a nanosecond. This new, bright, fast, narrowband, low-coherence light source opens the door to many exciting new applications in bio-imaging such as high-speed, wide-field microscopy.”
So the novel and new technique known as Random Raman lasing which provokes diffuse material such as a powder to emit laser light. This is quite different from traditional lasers that work by bouncing photons back and forth in a laser cavity. The property of Raman lasing happens when light bounces among the powder for a period which is adequate for amplification.
As per Hokr, Random Raman Laser Emission occurs in the range of single nanoseconds and a narrow spectrum of 0.1 nanometer. It can emit millions of photons per minute wavelength as compared to any other conventional source. It will suffice the requirements of the scientists to acquire a full two-dimensional fluorescent image in a single pulse of the laser.