We present a high power visible diode laser enabling a low-cost treatment of eye diseases by laser coagulation, including the two leading causes of blindness worldwide (diabetic retinopathy, age-related macular degeneration) as well as retinopathy of prematurely born children, intraocular tumors and retinal detachment. Laser coagulation requires the exposure of the eye to visible laser light and relies on the high absorption of the retina. The need for treatment is constantly increasing, due to the demographic trend, the increasing average life expectancy and medical care demand in developing countries. The World Health Organization reacts to this demand with global programs like the VISION 2020 “The right to sight” and the following Universal Eye Health within their Global Action Plan (2014-2019). One major point is to motivate companies and research institutes to make eye treatment cheaper and easily accessible. Therefore it becomes capital providing the ophthalmology market with cost competitive, simple and reliable technologies. Our laser is based on the direct second harmonic generation of the light emitted from a tapered laser diode and has already shown reliable optical performance. All components are produced in wafer scale processes and the resulting strong economy of scale results in a price competitive laser. In a broader perspective the technology behind our laser has a huge potential in non-medical applications like welding, cutting, marking and finally laser-illuminated projection.
Many laser applications require a circular, astigmatism-free, diffraction limited, high power beam. A tapered laser diode can generate up to 6 W output power in a diffraction limited beam. However the beam is elliptical and highly astigmatic rendering the design of beam shaping challenging. We present a diffraction limited beam shaping design, especially suitable to circularize and collimate highly astigmatic beams. The setup consists of a simple plano-convex cylindrical lens in the aplanatic condition and an asphere. The first lens matches the divergence of the fast- to the slow axis at the point where the beam is circular while the following asphere collimates the beam. The aplanatic condition is fulfilled by choosing a glass with a specific refractive index depending on the ratio between fast- and slow axis divergence. This cylindrical lens introduces neither spherical error nor primary coma, which makes it insensitive to misalignment. The setup has been tested with a high power laser diode at 980 nm with a 6 mm long taper (angle 6°) and a facet width of 425 μm. The optics have a transmission of about 90% and the resulting beam has a M<sup>2</sup> < 1.5. As a proof of principle 3.2 W were coupled into a 15 μm (NA 0.06) LMA fiber with 55% efficiency corresponding to a brightness B = 140 MW/(cm<sup>2</sup> sr). Furthermore the presented beam shaping can easily be extended to bars or multiple emitters to reach power levels that are to date only achievable with complex wavelength combination techniques.
We report on a new monolithic high-power diode pumped Er:YAG solid state laser at 2.94 µm. The pulsed laser reaches 30Waverage output power and 150mJ pulse energy. To accomplish these high powers the thermal lensing of Er:YAG was modeled beyond ABCD matrix formalism with FEM simulations. With the well understood thermal lensing e ect alternative laser cavities have been designed for higher brightness. The predicted results t the theoretically simulated performance and with that an improved beam quality factor of M2 = 12 has been achieved with 100mJ pulse energy.
Pantec Medical Laser presents a diode pumped Er:YAG laser for dental and hard tissue applications. The diode pumped
laser is practically maintenance free and ensures reliable operation over several thousand hours. The high repetition rate
with up to 15 W average output power, allows treatments otherwise not feasible with low repetition rate, lamp pumped
Er:YAG systems. The variable pulse duration of 10 to 200 μs combined with the good beam quality ensures precise and
fast treatment. First results on enamel ablation as well as the power scalability of the technology to 200 mJ and 30 W
average power are also shown.