Modulation Response of a Long-cavity, Gain- Levered Quantum-dot Semiconductor Laser -postprint

The gain-lever effect enhances the modulation efficiency of a semiconductor laser when compared to modulating the entire laser. This technique is investigated in a long-cavity multi-section quantum-dot laser where the length of the modulation section is varied to achieve 14:2, 15:1 and 0:16 gain-to-modulation section ratios. In this work, the gain-levered modulation configuration resulted in an increase in modulation efficiency by as much as 16 dB. This investigation also found that the 3-dB modulation bandwidth and modulation efficiency are dependent on the modulation section length of the device, indicating the existence of an optimal gain-to-modulation section ratio. The long cavity length of the multi-section laser yielded a distinctive case where characteristics of both the gain-lever effect and spatial effects are observed in the modulation response. Here, spatial effects within the cavity dominated the small-signal modulation response close to and above the cavity’s free-spectral range frequency, whereas the gain-lever effect influenced the modulation response throughout the entirety of the response. ©2014 Optical Society of America OCIS codes: (060.4080) Modulation; (230.5590) Quantum-well, -wire and -dot devices; (140.5960) Semiconductor lasers. References and links 1. K. J. Vahala, M. A. Newkirk, and T. R. Chen, “The optical gain lever: A novel gain mechanism in the direct modulation of quantum well semiconductor lasers,” Appl. Phys. Lett. 54(25), 2506–2508 (1989). 2. Y. Li, N. A. Naderi, V. Kovanis, and L. F. Lester, “Enhancing the 3-dB bandwidth via the gain-lever effect in quantum-dot lasers,” IEEE Photon. J. 2(3), 321–329 (2010). 3. T. B. Simpson, J. M. Liu, and A. Gavrielides, “Bandwidth enhancement and broad-band noise-reduction in injection-locked semiconductor-lasers,” IEEE Photon. Technol. Lett. 7(7), 709–711 (1995). 4. A. Murakami, K. Kawashima, and K. Atsuki, “Cavity resonance shift and bandwidth enhancement in semiconductor lasers with strong light injection,” IEEE J. Quantum Electron. 39(10), 1196–1204 (2003). 5. M. Radziunas, A. Glitzky, U. Bandelow, M. Wolfrum, U. Troppenz, J. Kreissl, and W. Rehbein, “Improving the modulation bandwidth in semiconductor lasers by passive feedback,” IEEE J. Sel. Top. Quantum Electron. 13(1), 136–142 (2007). 6. F. Grillot, C. Wang, N. A. Naderi, and J. Evan, “Modulation properties of self-injected quantum-dot semiconductor diode lasers,” IEEE J. Sel. Top. Quantum Electron. 19(4), 1900812 (2013). 7. M. Asada, Y. Mitamoto, and Y. Suematsu, “Gain and the threshold of three-dimensional quantum-box lasers,” IEEE J. Quantum Electron. 22(9), 1915–1921 (1986). 8. L. F. Lester, S. D. Offsey, B. K. Ridley, W. J. Schaff, B. A. Foreman, and L. F. Eastman, “Comparison of the theoretical and experimental differential gain in strained layer InGaAs/GaAs quantum well lasers,” Appl. Phys. Lett. 59(10), 1162–1164 (1991). 9. M. G. Thompson, A. R. Rae, M. Xia, R. V. Penty, and I. H. White, “InGaAs quantum-dot mode-locked laser diodes,” IEEE J. Sel. Top. Quantum Electron. 15(3), 661–672 (2009). 10. C. R. Doerr, “Direct modulation of long-cavity semiconductor lasers,” J. Lightwave Technol. 14(9), 2052–2061 (1996). 11. N. G. Usechak, M. Grupen, N. Naderi, Y. Li, L. F. Lester, and V. Kovanis, “Modulation effects in multi-section semiconductor lasers,” Proc. SPIE 7933, 793311 (2011). #196097 $15.00 USD Received 19 Aug 2013; revised 6 Nov 2013; accepted 8 Jan 2014; published 17 Jan 2014 (C) 2014 OSA 27 January 2014 | Vol. 22, No. 2 | DOI:10.1364/OE.22.001726 | OPTICS EXPRESS 1726 Approved for public release; distribution unlimited. 1 12. L. A. Coldren and S. W. Corzine, Diode Lasers and Photonic Integrated Circuits (John Wiley & Sons, Inc., 1995), pp. 204–207. 13. Y. Li, N. A. Naderi, Y.-C. Xin, C. Dziak, and L. F. Lester, “Multi-section gain-lever quantum dot lasers,” Proc. SPIE 6468, 646819 (2007). 14. N. Naderi, M. Pochet, F. Grillot, N. Terry, V. Kovanis, and L. F. Lester, “Modeling the injection-locked behavior of a quantum dash semiconductor laser,” IEEE J. Sel. Top. Quantum Electron. 15(3), 563–571 (2009). 15. L. A. Glasser, “A linearized theory for the diode laser in an external cavity,” IEEE J. Quantum Electron. 16(5), 525–531 (1980).