Pump diode lasers

Semicond. Sci. Technol.

Stojetz

et al. 2015

Catastrophic optical damage (COD) in 450 nm emitting InGaN/GaN diode lasers is artificially provoked by applying single sub-microsecond current pulses of increasing amplitude. Studying a batch of devices in which COD does not represent the main degradation mode, we find that COD is a 'hot' process. It becomes re-ignited in subsequent pulses. During the process, the spatial filamentation changes abruptly and the outer appearance of the damage pattern is predominantly created within the initial pulse. The process can cause material ejection out of the front facet as shown by thermography.

mentioning

confidence: 99%

Kinetics of catastrophic optical damage in GaN-based diode lasers

Semicond. Sci. Technol.

Stojetz

et al. 2015

“…The term "kink-free" stands here for an operation regime, where the device indeed works in single-spatial-mode operation without the presence of any higher order spatial modes 2. Higher order spatial modes are expected to have peak intensities in the waveguide part of the facet.…”

mentioning

confidence: 99%

Microscopic Origins of Catastrophic Optical Damage in Diode Lasers

IEEE J. Select. Topics Quantum Electron.

Mattina

et al. 2013

Extremely early phases of the catastrophic optical damage (COD) process in 808-nm emitting GaAs/Al 0 .35 Ga 0 .65 As high-power diode lasers are prepared by the application of short single current pulses. Typical energy entries during these pulses are on the order of 100 nJ within several 100 ns. The resulting defect pattern is investigated by high-resolution microscopy. The root of the COD is found to be located at the waveguide of the laser structure. Analysis of material composition modifications as a result of early COD phase points to melting being involved in the process. During recrystallization, an Al-rich pattern is formed that encloses a volume of a few cube micron of severely damaged material.

“…These tests led devices to sudden degradation, namely to the Catastrophic Optical Damage (COD) [10,11]. This generic degradation process relies on the local absorption of light and subsequent heating of the absorbing site, which increases absorption again.…”

Section: Resultsmentioning

confidence: 99%

Short-wavelength infrared defect emission as probe for degradation effects in diode lasers

Novel in-Plane Semiconductor Lasers XIV

Yue

et al. 2015

The infrared emission from 980-nm single-mode high power diode lasers is analyzed in the wavelength range from 0.8 to 7.0 µm. A pronounced short-wavelength infrared (SWIR) emission band with a maximum at 1.3 µm is found to originate from defect states located within the waveguide of the devices. The SWIR intensity is verified to represent a measure of the non-equilibrium carrier concentration in the waveguide, allowing for non-destructive waveguide mapping in spatially resolved detection schemes. The potential of this approach is demonstrated by measuring spatially resolved profiles of SWIR emission and correlating them with mid-wavelength infrared thermal emission along the cavity of devices undergoing repeated catastrophic optical damage. The enhancement of SWIR emission in the damaged parts of the cavity is due to a locally enhanced carrier density in the waveguide and allows for in situ analysis of the damage patterns. Moreover, spatial resolved SWIR measurements are a promising tool for device inspecting even in low-power operation regimes.