Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Development of room temperature 1.55µm InAs/InP quantum wire (QWR) lasers

Nature of the result:
Photoluminescence at room temperature of InAs QWR have been achieved at 1.55µm. Using the knowledge adquired in tuning the wavelength emission of QWR and stacked layer of QWR several laser have been grown and processed. asing at 1.45µm at 100K from a single layer QWR device has been obtained, and lasing up to 250K from a three layer QWR device with low threshold current. This result is directly related to D21 (and supersedes D3). The development and performance of these lasers from CSIC is state-of-the-art at this wavelength, and already shows Jth 4x lower than for comparative quantum well (QW) devices at the same wavelength.

Potential applications of the result:
This result is an important stepping stone to achieving 1.55µm lasers with nanostructures as the active material. As such strong competition with the current InP based QW lasers is expected for telecomms applications.

End-users of the result:
Telecommunications components manufacturers, telecommunications systems

Main innovative features/benefits:
1.55µm is the minimum attenuation point in standard optical fibre, the type of which is widely deployed around the planet. Dispersion however is non-zero, and as such any transmitter should have low or zero chirp to enable long distances to be spanned without regeneration. Reducing the dimensionality i.e. moving from quantum wells (current laser technology) to quantum wires (this work) is expected to lead to a concentration of the density of states at the lasing energy and a more symmetric gain profile within the device, resulting in a reduction in chirp.

Quantum confinement leads to an increase in the exciton binding energy and an increase in the oscillator strength enabling operation up to higher temperatures. If the laser can operate at high temperatures (85°C) then there is no need for a thermoelectric cooler. This represents a cost saving in terms of parts, assembly, control electronics and system cooling.

Analysis of market or application sectors:
1.55µm reduced chirp direct modulation QWR laser for 10GBits-1 over 80km reach.

Potential barriers:
There is currently no literature on high frequency operation of QWRs lasers at 1.55µm to confirm whether direct modulation at 10GBs-1 is realistic. The poor electron confining potential has to be improved before high temperature operation can be successful. Investigation of the stacking of the QWRs is needed to retain the correct emission wavelength as established for the single layer devices.
A less quantifiable but probably more significant barrier is the ongoing advancement of competing technologies. If significant progress can be made in improving the current QW based devices, then this market window may close.

Informazioni correlate

Reported by

IMM, Consejo Superior de Investigaciones Científicas (CSIC)
Isaac Newton, 8
28760 Tres Cantos, Madrid
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