Open AccessObservation of zero linewidth enhancement factor at excited state band in quantum dot laser
Author(s) -
Zubov F.I.,
Maximov M.V.,
Moiseev E.I.,
Savelyev A.V.,
Shernyakov Y.M.,
Livshits D.A.,
Kryzhanovskaya N.V.,
Zhukov A.E.
Publication year - 2015
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2015.2512
Subject(s) - laser linewidth , excited state , spectral line , laser , quantum dot , wavelength , quantum dot laser , materials science , atomic physics , ground state , physics , optoelectronics , optics , semiconductor laser theory , quantum mechanics
The linewidth enhancement factor (LEF) of an InAs/InGaAs quantum dot Fabry‐Pérot laser in a wide wavelength range from 1110 to 1300 nm, including ground state (GS) and exited state (ES) bands, is studied. LEF spectra were derived from amplified spontaneous emission spectra measured below the threshold in the pulse regime. The ES optical transition is characterised by significantly lower values of the LEF (≤0.54) as compared to the GS (≥1.21). Moreover, a zero LEF is observed within the ES spectral band. At sufficiently high currents, a near‐zero LEF (| α | ≤ 0.1) is achieved in a wide spectral interval from 1146 to 1175 nm, in which the optical gain is not less than 9 cm −1 .