Chip Technology

Lumics’ patented chip technology includes a proprietary laser diode facet passivation process. The chip design and the manufacturing process have been continuously optimized over the last 24 years, resulting in unmatched lifetime. The key features of the Lumics chip are summarized as follows:

The Lumics laser diodes are edge emitting ridge waveguide lasers, which is the proven and accepted concept of choice for applications that require very high power single mode or broad area diodes.

In order to ensure long life-time of the laser diodes the front and rear chip facet must be passivated to avoid degradation and catastrophic optical mirrow damage (COMD), Lumics has developed a unique process which allows to form a perfectly crystalline and virtually defect free passivation layer on the chip facet. This is the best in-class mirror protection. Its main purpose is to avoid light absorption, which would result in facet heating and oxidation of the Al-containing laser material.

The perfect crystalline passivation layer is non-absorbing down to very short wavelength of less than 750nm. Therefore, the Lumics chip technology offers high flexibility in wavelength.

A large percentage of the laser diodes manufactured in Lumics’ own in-house chip fab are based on a GaAs/AlGaAs heterostructure with InGaAs or GaInAsP active quantum well layers depending on wavelength. Other wavelengths are based on InP or GaSb structures.

The GaAs/AlGaAs compound semiconductor is the preferred material combination for highest power applications compared to Al-free materials, because of its superior intrinsic physical properties such as carrier confinement, thermal and electrical conductivity, and the possibility to allow more flexible refractive index variation in the waveguide design.

The main problem of AlGaAs is oxidation and defect generation on the chip facets after exposure to air. However, Lumics can take full advantage of the GaAs/AlGaAs material due to its unique facet passivation technique.

In summary, both the broad area and the single mode data from <25 years of lifetime testing show the extremely high COMD level of the Lumics laser diodes. Thus the Lumics technology with its facet passivation allows highest power density without having to make compromises on the flexibility in wavelength.

Optical output power vs. current in pulsed operation (13 µsec pulse 6.6 KHz) for a 94µm 915nm broad area emitter on Flat_mount at 25°C base temperature.