The paper reports on the wavelength stabilization of high-power laser diode multi-emitter modules using as the external reflectors fiber Bragg gratings that are directly inscribed into the large mode area module delivery fiber using a femtosecond laser. Experiments have been carried out in a 200 μm fiber at 976 nm, but the approach can be extended at other fiber diameters and wavelengths. The results have demonstrated an effective stabilization over a broad driving current range, with power penalties in line or slightly lower than those of more traditional architectures that make use of discrete components, such as volume Bragg gratings, but with the advantage of not requiring the alignment of additional elements.
This paper describes the family of blue laser modules developed in Convergent Photonics, relying on a proprietary architecture of spatial and polarization multiplexing and making use of the same platform and assembly lines of similar 9xx nm laser diode multi-emitters. This proprietary technology leads to high emitted power, together with unprecedented - for blue laser sources - low SWaP (Size Weight and Power consumption) and high brightness, suitable for a cost reduction over high volume productions. Present realization is an extremely compact (53 mm × 138 mm × 14.6 mm) laser source, based on a spatial and polarization multiplexing of 20 diodes, with a 114 um core / 125 um cladding multimode fiber output. Prototypes demonstrated power in excess of 100 W at 450 nm, with 95 % of emitted power filling only 0.15 numerical aperture (N.A.).
The paper describes the latest advancements in power upscaling of blue diode laser modules that rely on the same platform and assembly lines of the more common 9xx nm fiber coupled modules to obtain compact, high brightness, and high reliability devices. The new member of the family exploits a combination of spatial, polarization, and spectral multiplexing of wavelength stabilized chips to deliver up to about 180W in a 50 µm core - 0.22 numerical aperture fiber, with a beam parameter product lower than 4.5 mm · mrad. The high positioning accuracy enabled by the well tested machines used for the automatic assembly of the commercial off-the-shelf infrared multi-emitters allows using for the first time a single volume Bragg gratings to simultaneously lock an entire row of spatially multiplexed blue chips, easing the device manufacturability.
Blue laser diode sources have already proved to be an effective alternative for material processing, especially of high reflective materials, such as copper; now the challenge is to increase their power while improving brightness and reducing the cost-per-watt. The paper presents the development of a family of blue laser modules that, making use of the same platform and assembly lines of similar 9xx nm modules, can achieve an unprecedented combination of power, brightness, compactness and cost reduction. These modules rely on a proprietary architecture to combine a plurality of chips through spatial and polarization multiplexing, obtaining up to 100W of output power in a 100 μm fiber. Preliminary experimental results for module making use of spatial multiplexing report 35W output power in a 50 μm fiber.
A family of laser diode modules emitting hundreds of watt and based on intrinsically wavelength stabilized narrow linewidth high-power Distributed Bragg Reflector (DBR) chips has been manufactured and fully characterized. The module layout exploits a proprietary architecture to combine through spatial and wavelength multiplexing several highly manufacturable chips that integrate a grating and therefore do not require additional external stabilization devices to allow dense wavelength multiplexing. Power levels going from 200W to 400W in a 135 micron core fiber have been achieved using two to four wavelengths. The narrow spectral emission of each chip makes the modules suitable not only for direct-diode material processing, but also for laser pumping.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.