Catastrophic optical damage in GaAlAs/GaAs laser diodes

We studied catastrophic optical damage of mounted GaAlAs/GaAs double-heterostructure (DH) laser diodes by measuring structure-parameter influence and by EL, CL, EBIC and TEM observation. Several lasing characteristics depend on the resonator length as well as near-field width and lasing wavelength. Their influence on the optical damage power was estimated and compared with measured data. The TEM observations showed a periodic trace of DL growth. The defect spacing decreases exponentially from the mirror into the active region. The defects are surrounded by a stress field causing an increase in absorption. Because the EL images of mounted laser diodes showed in most cases damage to the front facet, we measured the mechanical stress under operating conditions. The unsymmetrical mounting (at the edge of the submount) causes a higher stress at the front facet than at the rear facet.