Design of praseodymium-doped chalcogenide micro-disk emitting at 4.7 µm.

A compact amplifier based on chalcogenide Pr³⁺-doped micro-disk coupled to two ridge waveguides is designed and refined by means of a home-made computer code. The gain G ≈ 7.9 dB is simulated for a Pr³⁺ concentration of 10 000 ppm, input signal power of -30 dBm at the wavelength 4.7 µm and input pump power of 50 mW at the wavelength 1.55 µm. In the laser behavior, i.e. without input signal, the maximum slope efficiency S = 8.1 × 10^-4 is obtained for an input pump power of 2 mW. This value is about six times higher than that simulated for an optimized erbium-doped micro-disk.