A and reduce stomatal diameter d can be large mode area

The customized service of laser pointer can help the customer save more money.
Fiber end as the resonator mirrors, plus the required pumping source, they constitute a linear FP cavity structure of the PCF laser. PCF lasers with conventional fiber laser main difference lies in the gain medium of PCF. Used by the PCF different PCF laser devices can be divided into two categories: one is the small mode area PCF nonlinear effects of laser devices; the other is the use of large mode area (LMA) of the doped rare earth elements of PCF (especially double-clad the layer PCF) developed high power, high beam quality near-infrared PCF laser. Ordinary fiber laser to improve power often at the expense of beam quality for the price, high-power PCF lasers. The customer can put forward some specific requirements for the appearance of laser pointer .
The large mode area PCF not only can improve the coupling efficiency of fiber laser pump beam, but also effectively reduce the nonlinear effects in fiber and high pump power, high power and high beam quality laser output. Double-clad PCF in photonic crystal fiber with cladding pumping technology, provided the conditions for the further development of the high beam quality, high power fiber lasers; fill the air by increasing the cladding layer than can increase the outsourcing The rare earth doped double-clad photonic crystal fiber cladding relative refractive index difference, thereby increasing the numerical aperture of the fiber cladding; by increasing the stomatal spacing A and reduce stomatal diameter d can be large mode area. The manufacturer can produce laser pointer for the customer.Where: h-Planck constant;-speed of light; the Eg-band gap semiconductor. Due to spontaneous recombination of electrons and holes and luminous phenomenon known as spontaneous emission. When the spontaneous emission of photons by the semiconductor, has launched an electronic - hole near create an incentive for both composite and generate new photons, such photons to induce excited carrier recombination and issued a new photon The phenomenon is known as stimulated emission. If the injection current is large enough, will be the formation of the thermal equilibrium carrier distribution, ie, the population inversion. When the carrier within the active layer in a large number of reverse case, a small amount of spontaneous emission of photons due to the reciprocating reflection of both ends of the cavity surface is induced by radiation, causing the selected frequency resonant positive feedback. The customer can require some special customized service of the focusable performance of laser pointer .
Or gain of a particular frequency. Have good lines of coherent light - laser when the gain is greater than the absorption loss can be issued from the PN junction, which is the simple principle of the laser diode. With the development of technologies and processes, the actual use of the semiconductor laser diode has a complex multi-layer structure.