Applications: Medical and BioMedical

QPC’s high brightness semiconductor laser technology is enabling diode lasers to be used directly in a new range of medical and biomedical applications where previously gas, liquid, or solid state lasers were the only solution.

A variety of medical applications today utilize diode lasers as either pump lasers or as direct diode sources for treatment because of their compact size, efficiency, low cost and ability to produce large optical energies. Hair removal, dental, ophthalmic, and other dermatological applications utilize diode laser light directly. The wavelength of the light is critical to the treatment efficacy, and laser illuminator is chosen to match the absorption of various skin, blood or organ constituents, or that of an injected dye. In many cases, the light is delivered through a fiber by way of a catheter or scope which needs to be extremely small, resulting in the need for high brightness fiber coupled diode lasers.

Spectroscopy and atomic physics typically requires that the semiconductor lasers are carefully designed to match the wavelength, spectral width and output power requirements of the atom or molecule being manipulated or examined. By illuminating a sample with the proper wavelength of laser light, one can determine the constituents, deliver energy to the sample in order to induce or control chemical reactions, heat and or cool, and even physically manipulate the sample.

Medical imaging is also an important emerging application of diode lasers. Traditional MRI technologies utilize the inherent electro-magnetic dipole associated with the water molecules to produce images within the human body. However, several organs (such as the lungs) are difficult to image effectively because of the lack of water present. In order to dramatically enhance magnetic resonance imaging in these applications, diode lasers are used to produce a spin polarized inert atomic vapor which is then delivered into the intended imaging area. The inert gas does not react with the organ being imaged, but its presence there enables the MRI technology to produce images with significantly higher resolution and contrast than ordinary MRI.

Typically, the diode lasers directly pump an alkali atomic vapor such as Rb, Cs, or K, and then that vapor transfers the polarization to an inert gas such as He3 or Xe via collisional spin exchange. Many applications beyond medical imaging are being explored with this technology such as the evaluation of structural integrity of bridges and buildings and searching for oil. In this application, semiconductor lasers are carefully designed to match the wavelength, spectral width and output power requirements of the atomics vapor being pumped.