Rare Earth Doped Integrated Optic Laser Glasses from Schott

Schott Glass Technologies has introduced two rare earth doped integrated optic laser glasses. These new glasses were developed for use in the fabrication of active guided wave structures by potassium and silver ion exchange. Thus, they can be used for waveguide laser substrates for generating telecommunication signals, waveguide amplifiers, and laser arrays for DWDM measurement tools.

IOG-1 is a sodium-aluminum-phosphate based glass that can be produced with a wide variety of different dopants and dopant combinations including, but not limited to, neodymium, thulium, erbium, ytterbium, praseodymium, and holmium. IOG-10 is a mixed alkali-zinc-silicate glass that has also found application with rare earth ions other than neodymium, including erbium, ytterbium, and both erbium and ytterbium in combination, as well as other rare earth ions and ion combinations.

Lasers made from these glasses can provide more power than currently available high-end diode lasers for WDM applications. Diode lasers typically output 2 - 20 mW. The power of lasers made from IOG-1 and IOG-10 is only limited by available pump power and values exceeding 200 mW have been demonstrated. Such power levels will allow the use of glass waveguide lasers in metropolitan area networks without the need for expensive optical amplifiers in the network.

Lasers made with IOG-1 and IOG-10 have other potential advantages compared to WDM diode source lasers. This long upper state lifetime of the Er laser manifold in glass suggests linewidths less than 100KHz should be possible, and a linewidth of 500kHz has already been demonstrated. As has been experienced with glass based active fiber systems, the low relative intensity noise (RIN) of solid state waveguide lasers is also expected to be a distinct advantage over semiconductor lasers for analog fiber telecommunications. In addition, minimal changes in refractive index of these glasses caused by exposure to high intensity laser radiation indicates possible improved wavelength stability over extended laser lifetimes.