Single-mode pump power source

Abstract

The mode and wavelength of a conventional, multi-mode, wide-stripe laser diode is converted in an Nd3+ ion-doped laser host crystal to a stable, single-mode output that falls within the spectral region required for pumping EDFA amplifying structures. The host crystal absorbs radiation from the diode that corresponds with the 4I9/2→4F5/2 absorption band of its Nd3+ ions, and re-radiates into the 4F3/2→4I9/2, 4F3/2→4I11/2, and 4F3/2→4I13/2 transitions which release photon energy that can be utilized by amplifying structures doped with Er3+ and/or Yb3+. The spatial mode of the multimode laser diode is converted to single-mode by enclosing the Nd3+-doped host laser crystal within a laser cavity that has a fundamental mode size large enough to encircle the spatial extent of the beam emanating from the laser diode.

Dependencies are inferred from the claim text.