ELUXI_Quantum_Dot_Lasers_and_Gain

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Single Mode Laser Diodes Broad Area Laser Diodes Comb Laser DFB and DBR Laser Diodes Gain Chips Gain Modules

Diode Lasers Line Narrowed Lasers Quantum Cascasde Lasers Quantum Dot Lasers and Gain Chips Tuneable ECDL_Lasers

Together with its partners ELUXI is able to offer a comprehensive range of solutions in this area. If you cannot find what you are looking for from the information below, please contact us directly.

QUANTUM DOT LASERS AND GAIN CHIPS

SEMICONDUCTOR LASERS

Quantum Dots

Features

Diode lasers and broadband light sources covering the unique wavelength range of 970nm - 1450nm
Offerings include
Laser Bars
Single Emitter
Multi Emitters
Direct beam
Fibre coupled modules

Quantum Dots

Lasers

Quantum dots are small semiconductor structures in a host medium with higher electronic (energy) bandgap. Dot dimensions typically range from 2 to 10 nm or ~10 to 50 atoms. More specifically, quantum dots for laser diodes are self-organized nanostructures that form spontaneously and controllably on a lattice-mismatched III-V substrate during epitaxial growth processes, like MBE or MOCVD. They function by localizing charge carriers, i.e., electrons and holes (excitons), through quantum confinement. This restricts the three translational degrees of freedom and can dramatically enhance useful electronic properties. At the moment, quantum dots are perhaps the best practical example of emerging nanotechnologies. Industrial applications range from optoelectronics and electronics to medical and biological.

Quantum dots constitute the gain medium in virtually all of Innolume’s semiconductor diode lasers and related products. This is because their composition, discreteness, and 3D carrier confinement provide valuable laser performance advantages over conventional quantum well heterostructures that offer only 1D confinement and exhibit strain limits. Benefits include reduced threshold current, temperature independence, broadened gain spectrum, and low relative intensity noise. Historically such advantages were more theoretical than practical since they were predicted on the basis of idealized quantum dot behaviour unperturbed by the host medium and structure. The reality is much more complicated. Full realization of the theoretical advantages has required years of MBE (molecular beam epitaxy) process development, heterostructure engineering, and device optimisation at Innolume’s Dortmund, Germany fab.

Today Innolume has achieved the promise of quantum dot nanotechnology for semiconductor lasers, as well as for associated optical devices like gain chips, semiconductor optical amplifiers (SOAs), light emitting diodes (LEDs), superluminescent diodes (SLDs), and single- or multi-mode laser bars. Achievements include: 1) demonstrated temperature independent laser performance from -20º to 90º C; 2) very broad lasing spectra (> 80 nm) with uniform intensity; 3) a unique comb laser diode permitting 10 Gb/s error free modulation of many high power (= 5 mW) channels; 4) stable and robust mode-locking at high peak power; and 5) overall laser performance competitive with the best quantum well diode lasers.

Innolume’s preferred compound semiconductor material system is InAs/GaAs, namely, indium arsenide quantum dots in gallium arsenide with aluminum gallium arsenide barriers, all on gallium arsenide substrates. The lasing wavelength window for this system is between 1064 nm and 1320 nm, controlled by quantum dot size, distribution, and indium concentration. Thus, Innolume’s quantum dot lasers fill the wavelength gap between quantum well lasers based on either GaAs (< 1100 nm) or InP (> 1300 nm). Furthermore, despite the relatively low concentration of the discrete gain medium, e.g., compared to continuous quantum well layers, quantum dots enable high power devices with high wall plug efficiency. For example, Innolume’s single-mode lasers in laser bars output 600 mW/laser and multimode laser bars output >8 W/laser, with 40% to 60% efficiencies depending on wavelength and modal details.

Innolume’s technologists have been intimately involved in quantum dot nanotechnology applied to optoelectronics for decades. Virtually all technical staff trained at the world-famous Ioffe Institute in St. Petersburg, Russia under Professor Alferov (2000 Nobel Laureate for laser heterostructure) and his colleagues. They worked all over the globe during the 1990s on MBE and laser technologies, agglomerating in 2003 under the Innolume umbrella in Dortmund to commercialise quantum dot nanotechnology. All phases of fabrication are done there, from MBE to packaging. To further consolidate its technology, in 2006 Innolume bought the only other company with quantum dot laser products, Zia Laser in New Mexico, USA.

Innolume offers diode lasers and broadband light sources covering an unique wavelength range of 1064nm - 1320nm based on its proprietary technologies of Quantum Dots.

Laser Bars as well as Single Emitter chips and fibre coupled modules are being offered.

Applications

medical/cosmetic laser systems
test & instrumentation equipment
gas sensing
defence systems
pumping

High power in unique wavelength range, for medical, cosmetics, materials processing and direct frequency conversion:

1064nm, 1210nm, 1320nm and custom wavelengths
600mW single-mode ex-facet
18W multi-mode ex-facet
250mW single-mode ex-fibre
12W multi-mode ex-fibre
100W+ multi-mode ex-fibre bundle

Gain Chips

Gain Chip (GC) is the irreplaceable component as a gain medium for the building of the tunable diode laser or high stable external cavity diode laser. Gain Chip is similar to laser diode chip except the fact that it has deep antireflecting coating on one or both facets which significantly increases threshold of self lasing or eliminate it.

Typical external cavity diode laser configurations are Littrow- and Littman/Metcalf cavities. For the Littrow configuration, a diffraction grating is mounted in a way that light of the desired wavelength is diffracted back along the incident beam. Wavelength is scanned by rotating the grating. Generally an intracavity achromatic lens is used to collimate expanded beam on a relatively large area of the grating. The zero order diffracted beam can be used as the output laser beam.

Littrow / Littman

Innolume Gain Chip product line subdividing in two main categories:

1. One side optical access (Types A and B)

2. Two sides optical access (Types C and D)

One side optical access Gain Chip is ideal component for operation in the scheme where the output power is outcoupled from the external cavity. Typically they are supplied in TO-can package.

Two sides optical access Gain Chip can be used in scheme allowing power outcoupling directly from the Gain Chip Facet to reduce the optical losses or in optical scheme for the amplification.

GainChip Types

Type A Gain Chip has straight stripe normal to the facets with high reflecting (HR) and deep antireflecting (AR) coatings. This is the most cost effective solution for the building of the external cavity diode laser. Type A GC has symmetrical beam far field providing efficient coupling to the external cavity and back using high NA aspheric lens. This type of the Gain Chips has relatively low gain spectra ripples suppression compare to the other types. It results from the fact that the reflection of the AR coated facet is on the level of 0.1% and can be further reduced by using slanted stripe-to-facer design only.

Type B GC has curved stripe with HR- on normal side and deep AR-coating on the tilted one. The slanted stripe together with deep AR-coating provides extremely low reflection (< 10E-5) allowing suppression of self lasing and minimizing of gain ripples. The drawback of the slanted stripe is the distortion of the output beam which embarrasses collimation and reduces efficiency of back coupling. High NA optics must be used.

Type C GC has curved stripe and deep AR-coating at the tilted side and a few percent reflection at the normal side. The wavelength selecting feedback has to be placed at the tilted side (with the same advantages and drawbacks as for the Type B), whereas the output power goes out from the normal side. This design allows high output power and relatively good output beam. The reflection of the facet with normal stripe has to be designed individually depending on the configuration of the system and required output power.

Type D GC has a tilted stripe with a deep AR on both sides, typically it used for the advanced optical schemes were the build-in amplifying unit is needed. Innovative facet coating technology which includes facet passivation meets high reliability requirements. The ISO9001:2008 conform production is based on careful design, manufacturing and extensive testing. Each device is individually tested and shipped with a specified set of test data.