Photonics Research, 2018, 6 (9): 09000908, Published Online: Sep. 5, 2018
Modulation properties of solitary and optically injected phased-array semiconductor lasers
Figures & Tables
Fig. 1. (a) Schematic of a phased array consisting of two laser waveguides, A and B , with each of width 2 a and an edge-to-edge separation of 2 d . (b) More details about the distribution of refractive indices n 1 , 2 , where g represents gain per unit length and α the background attenuation coefficient per unit length due to effects such as scattering and intervalence band absorption [43].
Fig. 2. Stability diagrams of the solitary phased array in the (d / a , γ N Δ Ω / 2 π ) plane for (a)–(d) P = 1.1 P th and (e)–(h) P = 2 P th . (a), (e) Purely real index, (b), (f) positive index guiding with gain-guiding, (c), (g) pure gain-guiding, and (d), (h) index antiguiding with gain-guiding. Blue (yellow) stands for stability (instability).
Fig. 3. Modulation frequency response of the solitary phased array at P = 1.1 P th . (a) Purely real index with d / a = 2.4 , (b) positive index guiding with gain-guiding with d / a = 1.35 , (c) pure gain-guiding with d / a = 1.25 , and (d) index antiguiding with gain-guiding with d / a = 1.01 . Red (blue) represents in-phase (out-of-phase) modulation.
Fig. 4. Modulation frequency response of the solitary phased array at P = 2 P th . (a) Purely real index with d / a = 1.75 , (b) positive index guiding with gain-guiding with d / a = 1.3 , (c) pure gain-guiding with d / a = 1.05 , and (d) index antiguiding with gain-guiding with d / a = 0.91 . Red (blue) represents in-phase (out-of-phase) modulation.
Fig. 5. Modulation frequency response of the solitary phased array at (a), (b) P = 1.1 P th and (c), (d) P = 2 P th for index antiguiding with gain-guiding. (a), (b) d / a , 0.5–1.01 and (c), (d) d / a , 0.5–0.91. (a), (c) In-phase modulation and (b), (d) out-of-phase modulation.
Fig. 6. Modulation frequency response of the solitary phased array for (a), (b)P = 1.1 P th and d / a = 0.97 , as well as (c), (d) P = 2 P th and d / a = 0.87 in the case of index antiguiding with gain-guiding. (a), (b) γ N Δ Ω / 2 π , 0 to − 9 GHz and (c), (d) γ N Δ Ω / 2 π , 0 to − 10 GHz . (a), (c) In-phase modulation and (b), (d) out-of-phase modulation.
Fig. 7. Modulation frequency response of the solitary phased array for (a) P = 1.1 P th and d / a = 1.01 , as well as (b) P = 2 P th and d / a = 0.91 in the case of index antiguiding with gain-guiding. Red (blue) represents laser A ( B ) . Here only laser A is modulated.
Fig. 8. Stability diagrams of the optically injected phased array in the (K , Δ f ) plane for (a) P = 1.1 P th and d / a = 1.01 , as well as for (b) P = 2 P th and d / a = 0.91 in the case of index antiguiding with gain-guiding. Blue (yellow) stands for stability (instability).
Fig. 9. Modulation frequency response of the optically injected phased array for different detuning frequencies Δ f and a fixed injection ratio K = 200 in the case of index antiguiding with gain-guiding, where (a), (b) P = 1.1 P th and d / a = 1.01 , as well as (c), (d) P = 2 P th and d / a = 0.91 . (a), (c) In-phase modulation and (b), (d) out-of-phase modulation.
Fig. 10. Modulation frequency response of the optically injected phased array for different injection ratios K and a fixed detuning frequency Δ f = 0 GHz in the case of index antiguiding with gain-guiding, where P = 2 P th and d / a = 0.91 . (a) In-phase modulation and (b) out-of-phase modulation.
Fig. 11. Modulation frequency response of the optically injected phased array for (a) P = 2 P th and (b) P = 5 P th in the case of index antiguiding with gain-guiding. (a) K = 160 and (b) K = 250 . Other parameters are d / a = 0.91 and Δ f = 20 GHz . Red (blue) represents in-phase (out-of-phase) modulation. Horizontal dashed line corresponds to the − 3 dB level.
Fig. 12. Modulation frequency response of the master-amplitude-modulated optically injected phased array for different injection ratios K and a fixed detuning frequency Δ f = 20 GHz in the case of index antiguiding with gain-guiding. Other parameters are P = 2 P th and d / a = 0.91 . Horizontal dashed line corresponds to the − 3 dB level.
Nianqiang Li, H. Susanto, B. R. Cemlyn, I. D. Henning, M. J. Adams. Modulation properties of solitary and optically injected phased-array semiconductor lasers[J]. Photonics Research, 2018, 6(9): 09000908.