center wavelength 1532.5 ± 1.5nm
linewidth: <2nm FWHM
spectrum: Reduced sensitivity to temperature
and slow axis collimation available
and medical: Pumping of fiber and solid state Er:YAG lasers
and security: High energy lasers at eye-safe wavelengths
pumping efficiency for Er:YAG
thermal requirements of system
costly external optical components
laser diodes today are highly efficient but suffer from broad
linewidth, lack of control over center wavelength, and significant
dependence versus temperature.
In order to overcome these challenges and leverage
a novel technique of wavelength stabilization based on internal
diffraction gratings embedded inside the semiconductor chip was
developed for the QPC
product line. These devices are fabricated using a wafer-based process,
with the gratings defined after a first epitaxial growth by optical
lithography into a photoresist layer, followed by etching, then
finalized during a re-growth process. The process has been successfully
implemented in both GaAs and InP material at various wavelengths such
as 795nm, 808nm, 976nm, 981nm, 1453nm, 1532nm and 1908nm.
Figure 1: Schematic of Brightlock®
embedded grating written at wafer level during MOCVD epitaxial growth
(left). Atomic Force Microscope picture of internal grating (right).
InP or GaAs bars grown by MOCVD, Laser Operations manufactures kW-class
micro-channel cooled stacked arrays for resonant pumping.
Figure 2: Picture of 4 x 42 bar
vertical diode array of
Brightlock® bars at 1532nm (right). The arrays are collimated in fast
and slow axis to less than two degrees (FWHM). Power versus current and
spectrum of 1.4nm for the full 4 stacks module is shown (left).
Warning: Class 4
Laser. Invisible Laser Radiation – Avoid Eye or Skin Exposure
to Direct or Scattered Radiation.