Properties of a tunneling injection quantum-well laser: Recipe for 'cold' device with a large modulation bandwidth

Sun, Haitao; Davis, L.; Sethi, S.; Singh, Jasprit; Bhattacharya, P.

doi:10.1109/68.238238

Cited by 74 publications

(31 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A tunnel injection structure similar to that which has previously been used to reduce the temperature sensitivity of QW structures [2] has recently been applied to QD structures [3]. The tunnelling process is designed to inject carriers from an adjacent QW into the lower energy dot states so that relaxation from the wetting layer is no longer required.…”

mentioning

confidence: 99%

Selectively Populating a Quantum Dot Ensemble Using a Tunnel Injection Structure

George

Smowton

et al. 2007

2007 Conference on Lasers and Electro-Optics (CLEO)

Self Cite

View full text Add to dashboard Cite

We have analysed the carrier distribution of a tunnel injection quantum dot laser to reveal features which suggest dots of a particular size are preferentially populated during the tunnel injection process.Self-assembled quantum dot (QD) lasers have been developed with low threshold current densities, high differential gain and low temperature sensitivity as compared to lasers containing quantum wells (QW) [1]. Further improvements to their performance can be made by reducing the size non uniformity of the dot ensemble and the influence of the closely spaced wetting layer on the carrier population of the lower dot states.A tunnel injection structure similar to that which has previously been used to reduce the temperature sensitivity of QW structures[2] has recently been applied to QD structures [3]. The tunnelling process is designed to inject carriers from an adjacent QW into the lower energy dot states so that relaxation from the wetting layer is no longer required. Previous analysis of the carrier dynamics in tunnel injection quantum dot structures [4] has shown that these devices have low temperature sensitivity and, compared to other self assembled QD structures, they have a large small-signal bandwidth. In this paper we analyse the carrier distribution within a 1.24µm tunnel injection QD laser and reveal a selection process in which dots of a particular size are preferentially occupied.The devices were grown by molecular beam epitaxy on a (001) GaAs substrate and contain five repeat layers within the active region. Each layer consists of 2.6ML of InAs QDs capped with 45Å In 0.15 Ga 0.85 As. These are grown on top of a 95Å In 0.27 Ga 0.73 As injector well which is separated form the dot by a 15Å Al 0.25 Ga 0.75 As barrier. Further details of the structure and growth can be found in [5]. The tunnelling process is illustrated in Figure 1.The samples were tested using the segmented contact method[6] to produce carrier distribution (P f ) spectra as a function of photon energy. The P f spectra are produced from the ratio of the gain and spontaneous emission spectra as a function of photon energy (E=hv). The value of P f over a particular energy range reflects the degree of inversion of a state over that range. If all the carriers are distributed according to Fermi-Dirac statistics (thermally distributed) and described by the same quasi Fermi level separation ? E f, then P f at a particular temperature T can be described by:The spontaneous emission spectra at 300 K (figure 2) shows that the peak energies of the ground and excited state do not vary with carrier density. This suggests there is a non-thermal carrier distribution present. In addition, there is little recombination from the dot second excited state, which is consistent with the injection of carriers into the first excited state with little subsequent redistribution.In Figure 3 we plot the carrier distribution function at 300K , we also include the peak energies of the spontaneous emission ground and 1 st excited states on these spectra for reference. ...

show abstract

mentioning

confidence: 99%

Selectively Populating a Quantum Dot Ensemble Using a Tunnel Injection Structure

George

Smowton

et al. 2007

2007 Conference on Lasers and Electro-Optics (CLEO)

Self Cite

View full text Add to dashboard Cite

show abstract

“…A periodic superlattice (SL) has been embedded into the intrinsic region of a p-i-n diode, exhibiting a resonant behavior of the electroluminescence (EL) efficiency and an efficient occupation of the excited subbands by sequential resonant tunneling [3]. In regard to the waveguide devices, a tunneling injection laser has been demonstrated [4]. The electrons in this device are injected into the active lasing region via resonant tunneling through the double barrier structure.…”

mentioning

confidence: 99%

Multiple wavelength electroluminescence and laser generation in p-i-n resonant tunneling heterostructures

Торопов

Shubina

Lebedev

et al. 1998

Superlattices and Microstructures

View full text Add to dashboard Cite

“…The carrier capture time of the electron from a barrier-region (3D) to a ground state of QW (2D) was measured as 50 picoseconds in a 30Å-width QW [2]. A tunnel injection quantum well (TI-QW) structure was proposed by P. Bhattacharya to reduce dumping of the operation speed caused by the capture time [3]. The TI-QW lasers are expected to make it possible to directmodulation above 40Gb/s [4] and high efficiency operation by low Auger recombination rate and reduced hot electron [5].…”

mentioning

confidence: 99%

Theoretical design of carrier injection rate and recombination rate in tunnel injection quantum well lasers

Higa

Miyamoto

Nakajima

et al. 2008

Phys. Status Solidi (c)

View full text Add to dashboard Cite

Carrier injection rate in tunnel injection quantum well structures used in semiconductor lasers was investigated through theoretical analysis. Carrier capture time from 3D‐state to 2D‐state in a conventional quantum well was several ten picoseconds and it is almost uncontrollable characteristics. The tunnel injection structure can be designed to control the carrier injection rate. The carrier transition time from carrier reservoir‐region of the tunnel injection structure to the active well was a few picoseconds when the structure was designed for high speed transition. As results, carrier injection to ground state of the active well takes less than 10 picoseconds. The change of the radiative recombination rate in the active well also defines the optimal design of the tunnel injection structure. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

Properties of a tunneling injection quantum-well laser: Recipe for 'cold' device with a large modulation bandwidth

Cited by 74 publications

References 8 publications

Selectively Populating a Quantum Dot Ensemble Using a Tunnel Injection Structure

Selectively Populating a Quantum Dot Ensemble Using a Tunnel Injection Structure

Multiple wavelength electroluminescence and laser generation in p-i-n resonant tunneling heterostructures

Theoretical design of carrier injection rate and recombination rate in tunnel injection quantum well lasers

Contact Info

Product

Resources

About