Reduced Threshold Current and Enhanced Extinction Ratio in a Magnetically Controllable Fe₅₀Co₅₀–InGaAlAs/InP Nonreciprocal Semiconductor Laser

Abstract

We report on reduced threshold current and enhanced extinction ratio of a magnetically controllable Fe50Co50–InGaAlAs/InP nonreciprocal semiconductor laser. The improved device performance was consistent with calculated results for the modified layer structure and the use of ferromagnetic metal (Fe50Co50). The fabricated laser showed a threshold current 2.0 times smaller than our previous device having Fe. The extinction ratio, defined as the change in light intensity upon magnetization reversal, increased upon the appearance of the first-order transverse mode and reached 46% at a current of 100 mA. The reduced threshold current and enhanced extinction ratio should be useful for realizing low-operating-current, all-optical, robust signal processing devices using nonreciprocal semiconductor lasers.

Characterization of Transverse Magneto-optic Kerr Effect in Ferromagnetic Metals for Semiconductor Optical Isolators

“…III-V-or Si-based semiconductor optical isolators that work on the principle of nonreciprocal loss, [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] nonreciprocal phase shift, 23,24) nonreciprocal polarization rotation, [25][26][27] and surface plasmons 28,29) have been reported. Those based on nonreciprocal loss are typically composed of semiconductor optical amplifier (SOA) waveguides containing ferromagnetic metals such as Fe, Co, Ni, and other compound ferromagnetic metals.…”

“…We have used Fe as a ferromagnetic metal in transverse electric (TE-) mode semiconductor optical isolators 6,8,17,20) and transverse magnetic (TM-) mode semiconductor optical isolators. 21,22) In Refs. 7, 9, and 10, Fe 10 Co 90 and Fe 50 Co 50 were used in TM-mode semiconductor optical isolators operating at a wavelength of 1300 nm.…”