Publications

T. Hirooka and A. Hasegawa, "Chirped soliton interaction in strongly dispersion managed WDM systems," Optics Letters, vol. 23, no. 10, pp. 768-770, May 1998. [Optics InfoBase]
T. Hirooka and A. Hasegawa, "Quasi-soliton propagation with periodic optical phase conjugation," Electronics Letters, vol. 34, no. 21, 2056-2057, Oct. 1998. [IOJ]
T. Hirooka and S. Wabnitz, "Stabilization of dispersion-managed soliton transmissions by nonliear gain," Electronics Letters, vol. 35, no. 8, pp. 655-657, April 1999. [IOJ]
A. Hasegawa and T. Hirooka, "Stable filter control in wavelength division multiplexed soliton systems," Electronics Letters, vol. 36, no. 1, pp. 68-70, Jan. 2000. [IOJ]
T. Hirooka and S. Wabnitz, "Nonlinear gain control of dispersion managed soliton amplitude and collisions," Optical Fiber Technology, vol. 6, no. 2, pp. 109-121, April 2000. [IDEAL]
T. Hirooka, T. Nakada, and A. Hasegawa, “Feasibility of densely dispersion managed soliton transmission at 160 Gb/s,” IEEE Photonics Technology Letters, vol. 12, no. 6, pp. 633-635, June 2000. [IEEE Xplore]
I. Nishioka, T. Hirooka, and A. Hasegawa, “Effect of map strength on polarization mode dispersion in dispersion-managed soliton systems,” IEEE Photonics Technology Letters, vol. 12, no. 11, pp. 1480-1482, Nov. 2000. [IEEE Xplore]
M. J. Ablowitz and T. Hirooka, “Resonant nonlinear intrachannel interactions in strongly dispersion-managed transmission systems,” Optics Letters, vol. 25, no. 24, pp. 1750-1752, Dec. 2000. [Optics InfoBase]
M. J. Ablowitz, T. Hirooka, and G. Biondini, “Quasi-linear optical pulses in strongly dispersion-managed transmission systems,” Optics Letters, vol. 26, no. 7, pp. 459-461, Apr. 2001. [Optics InfoBase]
M. J. Ablowitz and T. Hirooka, “Nonlinear effects in quasi-linear dispersion-managed pulse transmission,” IEEE Photonics Technology Letters, vol. 13, no. 10, pp. 1082-1084, Oct. 2001. [IEEE Xplore]
M. J. Ablowitz and T. Hirooka, “Intra-channel pulse interactions in dispersion-managed transmission systems: timing shifts,” Optics Letters, vol. 26, no. 23, pp. 1846-1848, Dec. 2001. [Optics InfoBase]
M. J. Ablowitz and T. Hirooka, “Intra-channel pulse interactions in dispersion-managed transmission systems: energy transfer,” Optics Letters, vol. 27, no. 3, pp. 203-205, Feb. 2002. [Optics InfoBase]
M. J. Ablowitz and T. Hirooka, “Managing nonlinearity in strongly dispersion-managed optical pulse transmission,” Journal of the Optical Society of America B, vol. 19, no. 3, pp. 425-439, March 2002. [Optics InfoBase]
M. J. Ablowitz, G. Biondini, A. Biswas, A. Docherty, T. Hirooka, and S. Chakravarty, “Collision-induced timing shifts in dispersion managed solitons systems,” Optics Letters, vol. 27, no. 5, pp. 318-320, March 2002. [Optics InfoBase]
T. Hirooka and M. J. Ablowitz, “Suppression of intra-channel dispersion-managed pulse interactions by distributed amplification,” IEEE Photonics Technology Letters, vol. 14, no. 3, pp. 316-318, March 2002. [IEEE Xplore]
T. Hirooka and M. J. Ablowitz, “Analysis of timing and amplitude jitter due to intra-channel dispersion-managed pulse interactions,” IEEE Photonics Technology Letters, vol. 14, no. 5, pp. 633-635, May 2002. [IEEE Xplore]
M. J. Ablowitz and T. Hirooka, “Resonant intra-channel pulse interactions in dispersion-managed transmission systems,” IEEE Journal of Selected Topics in Quantum Electronics, vol. 8, no. 3, pp. 603-615, May/June 2002. [IEEE Xplore]
M. J. Ablowitz, T. Hirooka, and T. Inoue, “Higher-order asymptotic analysis of dispersion-managed transmission systems: solutions and their characteristics,” Journal of the Optical Society of America B, vol. 19, no. 12, pp. 2876-2885, Dec. 2002. [Optics InfoBase]
M. J. Ablowitz, A. Docherty, and T. Hirooka, “Incomplete collisions in strongly dispersion managed return-to-zero communication systems,” Optics Letters, vol. 28, no. 14, pp. 1191-1193, July 2003. [Optics InfoBase]
T. Hirooka and M. Nakazawa, “Parabolic pulse generation using a dispersion decreasing fiber with normal group velocity dispersion,” Optics Letters, vol. 29, no. 5, pp. 498-500, March 2004. [Optics InfoBase]
M. Nakazawa, T. Hirooka, F. Futami, and S. Watanabe, “Ideal distortion-free transmission using optical Fourier transformation and Fourier transform-limited optical pulses,” IEEE Photonics Technology Letters, vol. 16, no. 4, pp. 1059-1061, April 2004.
T. Hirooka, Y. Hori, and M. Nakazawa, “Gaussian and sech approximations of mode field profiles in photonic crystal fibers,” IEEE Photonics Technology Letters, vol. 16, no. 4, pp. 1071-1073, April 2004.
T. Hirooka, M. Nakazawa, F. Futami, and S. Watanabe, “A new adaptive equalization scheme for 160 Gbit/s transmitted signals using time-domain optical Fourier transformation,” IEEE Photonics Technology Letters, vol. 16, no. 10, pp. 2371-2373, Oct. 2004.
M. Nakazawa and T. Hirooka, “Distortion-free transmission of ultrashort optical pulses using time-domain optical Fourier transformation,” Japanese Journal of Optics, vol. 34, no. 1, pp. 26-31, Jan. 2005. (in Japanese)
T. Hirooka, S. Ono, K. Hagiuda, and M. Nakazawa, “Stimulated Brillouin scattering in dispersion-decreasing fiber with ultrahigh-speed femtosecond soliton pulse compression,” Optics Letters, vol. 30, no. 4, pp. 364-366, Feb. 2005.
K. Hagiuda, T. Hirooka, M. Nakazawa, S. Arahira, and Y. Ogawa, “40-GHz, 100-fs stimulated-Brillouin-scattering-free pulse generation by combining a mode-locked laser diode and a dispersion-decreasing fiber,” Optics Letters, vol. 30, no. 6, pp. 670-672, March 2005.
H. Hasegawa, T. Hirooka, and M. Nakazawa, “A new method for optimum dispersion designing of zero-dispersion and dispersion-flattened photonic crystal fibers,”IEICE Transactions on Electronics, vol. J88-C, no. 7, pp. 519-527, July 2005. (in Japanese)
T. Hirooka, M. Nakazawa, F. Futami, and S. Watanabe,“Ultrahigh-speed distortion-free optical pulse transmission using time-domain optical Fourier transformation,”IEICE Transactions on Communications, vol. J88-B, no. 8, pp. 1402-1410, Aug. 2005. (in Japanese)
M. Nakazawa and T. Hirooka, “Distortion-free optical transmission using time-domain optical Fourier transformation and transform-limited optical pulses,” Journal of the Optical Society of America B, vol. 22, no. 9, pp. 1842-1855, Sep. 2005.
H. Hasegawa, M. Kikegawa, M. Yoshida, T. Hirooka, and M. Nakazawa,“Observation of optimum air-hole tapering of splicing between a conventional fiber and a photonic crystal faiber and analysis of reduction of Fresnel reflection,” IEICE Transactions on Electronics, vol. J88-C, no. 10, pp. 779-787, Oct. 2005. (in Japanese)
M. Nakazawa and T. Hirooka, “ABCD matrix formalism of time-domain optical Fourier transformation for distortion-free pulse transmission,” IEICE Electronics Express, Vol. 3, no. 4, pp. 74-79, Feb. 2006.
H. Hasegawa, Y. Oikawa, M. Yoshida, T. Hirooka, and M. Nakazawa, “10 Gb/s transmission over 5 km at 850 nm using single-mode photonic crystal fiber, single-mode VCSEL, and Si-APD,” IEICE Electronics Express, vol. 3, no.6, pp. 109-114, March 2006.
M. Nakazawa, S. Nakahara, T. Hirooka, M. Yoshida, T. Kaino, and K. Komatsu, “Polymer saturable absorber materials in the 1.5 mm band using poly-methyl-methacrylate and polystyrene with single-wall carbon nanotubes and their application to a femtosecond laser,” Optics Letters, vol. 31, no. 7, pp. 915-917, April 2006.
T. Hirooka and M. Nakazawa, “Optical adaptive equalization of high-speed signals using time-domain optical Fourier transformation,” Invited paper, Journal of Lightwave Technology, vol. 24, no. 7, pp. 2530-2540, July 2006.
Y. Oikawa, H. Hasegawa, T. Hirooka, M. Yoshida, and M. Nakazawa,“Ultra-broadband dispersion measurement of photonic crystal fiber with pico-second streak camera and group-delay-free supercontinuum,”IEICE Transactions on Communications, vol. J89-C, no. 7, pp. 450-457, July 2006. (in Japanese)
T. Hirooka, T. Kumakura, K. Osawa, and M. Nakazawa, “Comparison of 40 GHz optical demultiplexers using SMZ switch and EA modulator in 160 Gbit/s-500 km OTDM transmission,” IEICE Electronics Express, vol. 3, no. 17, pp. 397-403, September 2006.
M. Nakazawa and T. Hirooka,“Recent progress and future prospects for high-speed optical transmission technology using an ultrashort optical pulse train,”Invited paper, IEICE Transactions on Communications, vol. J89-B, no. 11, pp. 2067-2081, Nov. 2006. (in Japanese)
T. Hirooka, K. Hagiuda, T. Kumakura, K. Osawa, and M. Nakazawa, “160 Gb/s-600 km OTDM transmission using time-domain optical Fourier transformation,” IEEE Photonics Technology Letters, vol. 18, no. 24, pp. 2647-2649, Dec. 2006.
M. Nakazawa, M. Yoshida, and T. Hirooka, “Ultra-stable regeneratively mode-locked laser as an opto-electronic microwave oscillator and its application to optical metrology,” IEICE Transactions on Electronics, Invited paper, vol. E90-C, no. 2, pp. 443-449, February 2007.
Y. Oikawa, H. Hasegawa, K. Suzuki, Y. Inoue, T. Hirooka, and M. Nakazawa, “4x10 Gb/s WDM transmission over a 5-km-long photonic crystal fiber in the 800-nm region,” IEEE Photonics Technology Letters, vol. 19, no. 8, pp. 613-615, April 2007.
H. Hasegawa, Y. Oikawa, T. Hirooka, and M. Nakazawa, “40 Gbit/s-2 km photonic crystal fiber transmission with 850 nm singlemode VCSEL,” Electronics Letters, vol. 43, no. 11, pp. 642-644, May 2007.
M. Nakazawa, T. Hirooka, and M. Yoshida, "Optical fiber transmission of standard signals using optical combs,” The Review of Laser Engineering (in Japanese), vol. 35, no. 10, pp. 649-653, October (2007).
T. Hirooka, M. Nakazawa, and K. Okamoto, “Bright and dark 40 GHz parabolic pulse generation using a picosecond optical pulse train and an arrayed waveguide grating,” Optics Letters, vol. 33, no. 10, pp. 1102-1104, May 2008.
T. Hirooka, M. Okazaki, and M. Nakazawa, “A straight-line 160-Gb/s DPSK transmission over 1000 km with time-domain optical Fourier transformation,” IEEE Photonics Technology Letters, vol. 20, no. 13, pp. 1094-1096, July 2008.
H. T. Quynhanh, A. Suzuki, M. Yoshida, T. Hirooka, and M. Nakazawa, “A l/4-shifted distributed-feedback laser diode with a fiber ring cavity configuration having an OSNR of 85 dB and a linewidth of 7 kHz,” IEEE Photonics Technology Letters, vol. 20, no. 18, pp. 1578-1580, September 2008.
T. Hirooka, K. Osawa, M. Okazaki, M. Nakazawa, and H. Murai, “Stimulated Brillouin scattering in ultrahigh-speed in-phase RZ and CS-RZ OTDM transmission,” IEEE Photonics Technology Letters, vol. 20, no. 20, pp. 1694-1696, October 2008.
T. Hirooka and M. Nakazawa, “All-optical 40-GHz time-domain Fourier transformation using XPM with a dark parabolic pulse,” IEEE Photon. Technol. Lett., vol. 20, no. 22, pp. 1869-1871, November 2008.
T. Hirooka, M. Okazaki, P. Guan, and M. Nakazawa, “320-Gb/s single-polarization DPSK transmission over 525 km using time-domain optical Fourier transformation,” IEEE Photon. Technol. Lett., vol. 20, no. 22, pp. 1872-1874, November 2008.
M. Okazaki, P. Guan, T. Hirooka, M. Nakazawa, and T. Miyazaki, “160-Gb/s 200-km field transmission experiment with large PMD using a time-domain optical Fourier transformation technique,” IEEE Photon. Technol. Lett., vol. 20, no. 24, pp. 2192-2194, December 2008.
T. Hirooka, M. Okazaki, T. Hirano, P. Guan, M. Nakazawa, and S. Nakamura, “All-optical demultiplexing of 640-Gb/s OTDM-DPSK signal using a semiconductor SMZ switch,” IEEE Photon. Technol. Lett., vol. 21, no. 20, pp. 1574-1576, October 2009.
P. Guan, M. Okazaki, T. Hirano, T. Hirooka, and M. Nakazawa, “Low-penalty 5x320 Gbit/s/single-channel WDM DPSK transmission over 525 km using time-domain optical Fourier transformation,” IEEE Photon. Technol. Lett., vol. 21, no. 21, pp. 1579-1581, November 2009.
K. Koizumi, M. Yoshida, T. Hirooka, and M. Nakazawa, “10 Gbit/s photonic crystal fiber transmissions with 1.1 mm directly-modulated single-mode VCSEL,” IEICE Electron. Express, vol. 6, no. 22, pp. 1615-1620, November 2009.
K. Kasai, T. Omiya, P. Guan, M. Yoshida, T. Hirooka, and M. Nakazawa, “Single-channel 400-Gb/s OTDM-32 RZ/QAM coherent transmission over 225 km using an optical phase-locked loop technique,” IEEE Photon. Technol. Lett., vol. 22, no. 8, pp. 562-564, April 2010.
T. Hirano, P. Guan, T. Hirooka, and M. Nakazawa, “640-Gb/s/channel single-polarization DPSK transmission over 525 km with ultrafast time-domain optical Fourier transformation,” IEEE Photon. Technol. Lett., vol. 22, no. 14, pp. 1042-1044, July 2010.
P. Guan, H. C. Hansen Mulvad, K. Kasai, T. Hirooka, and M. Nakazawa, “High Time-Resolution 640-Gb/s Clock Recovery Using Time-Domain Optical Fourier Transformation and Narrowband Optical Filter,” IEEE Photon. Technol. Lett., vol. 22, no. 23, pp. 1735-1737, December 2010.
P. Guan, H. C. Hansen Mulvad, Y. Tomiyama, T. Hirano, T. Hirooka, and M. Nakazawa, “Single-channel 1.28 Tbit/s-525 km DQPSK transmission using ultrafast time-domain optical Fourier transformation and nonlinear optical loop mirror,” IEICE Trans. Comm., vol. E94-B, no. 2, pp. 430-436, February 2011.
T. Hirooka, T. Hirano, P. Guan, and M. Nakazawa, “PMD-induced crosstalk in ultrahigh-speed polarization-multiplexed optical transmission in the presence of PDL,” J. Lightwave Technol., vol. 29, no. 19, pp. 2963-2970, October 2011.
Y. Tomiyama, K. Harako, P. Guan, T. Hirooka, and M. Nakazawa, “Comparison between polarization-multiplexed DPSK and single-polarization DQPSK in 640 Gbaud, 1.28 Tbit/s?500 km single-channel transmission,” Opt. Fiber Technol., invited paper, vol. 17, no. 5, pp. 439-444, October 2011.
K. Koizumi, M. Yoshida, T. Hirooka, and M. Nakazawa, “10 GHz, 1.1 ps optical pulse generation from a regeneratively mode-locked Yb fiber laser in the 1.1 μm band,” Opt. Express, vol. 19, no. 25, pp. 25426-25432, December 2011.
P. Guan, T. Hirano, K. Harako, Y. Tomiyama, T. Hirooka, and M. Nakazawa, “2.56 Tbit/s/ch Polarization-Multiplexed DQPSK Transmission over 300 km Using Time-Domain Optical Fourier Transformation,” Opt. Express, vol. 19, no. 26, pp. B567-B573, December 2011.
M. Nakazawa, K. Kasai, M. Yoshida, and T. Hirooka, “Novel RZ-CW conversion scheme for ultra multi-level, high-speed coherent OTDM transmission,” Opt. Express, vol. 19, no. 26, pp. B574-B580, December 2011.
M. Nakazawa, T. Hirooka, P. Ruan, and P. Guan, "Ultrahigh-speed “orthogonal” TDM transmission with an optical Nyquist pulse train," Opt. Express vol. 20, no. 2. pp. 1129-1140, January 2012.
M. Nakazawa, T. Hirooka, M. Yoshida, and K. Kasai, “Ultrafast coherent optical transmission,” IEEE J. Sel. Top. Quantum Electron., vol. 18, no. 1, pp. 363-376, January 2012.
K. Kasai, D. O. Otuya, M. Yoshida, T. Hirooka, and M. Nakazawa, “Single-Carrier 800-Gb/s 32 RZ/QAM Coherent Transmission Over 225 km Employing a Novel RZ-CW Conversion Technique,” IEEE Photon. Technol. Lett., vol. 24, no. 5, pp. 416-418, March 2012.
M. Nakazawa, M. Yoshida, and T. Hirooka, “Nondestructive measurement of mode couplings along a multi-core fiber using a synchronous multi-channel OTDR,” Opt. Express, vol. 20, no. 11, pp. 12530-12540, May 2012.
T. Hirooka, P. Ruan, P. Guan, and M. Nakazawa, “Highly dispersion-tolerant 160 Gbaud optical Nyquist pulse TDM transmission over 525 km,” Opt. Express, vol. 20, no. 14, pp. 15001-15008, July (2012).
K. Toyoda, Y. Koizumi, T. Omiya, M. Yoshida, T. Hirooka, and M. Nakazawa, “Marked performance improvement of 256 QAM transmission using a digital back-propagation method,” Opt. Express, vol. 20, no. 18, pp. 19815-19821, August (2012).
T. Hirooka and M. Nakazawa, “Linear and nonlinear propagation of optical Nyquist pulses in fibers,” Opt. Express, vol. 20, no. 18, pp. 19836-19849, August (2012).
Y. Koizumi, K. Toyoda, T. Omiya, M. Yoshida, T. Hirooka, and M. Nakazawa, "512 QAM transmission over 240 km using frequency-domain equalization in a digital coherent receiver," Opt. Express vol. 20, no. 21, pp. 23383-23389, September (2012).
T. Ono, Y. Hori, M. Yoshida, T. Hirooka, M. Nakazawa, J. Mata, and J. Tsukamoto, “A 31 mW, 280 fs passively mode-locked fiber soliton laser using a high heat-resistant SWNT/P3HT saturable absorber coated with siloxane,” Opt. Express vol. 20, no. 21, pp. 23659?23665, October (2012).
K. Koizumi, M. Yoshida, T. Hirooka, and M. Nakazawa, “160 Gbit/s-300 km single-channel transmission in the 1.1 μm band with a precise GVD and slope compensation,” Opt. Express, vol. 21, no. 4, pp. 4303-4310, February (2013).
T. Hirooka, K. Harako, P. Guan, and M. Nakazawa, “Second-order PMD-induced crosstalk between polarization-multiplexed signals and its impact on ultrashort optical pulse transmission,” J. Lightwave Technol. vol. 31, no. 5, pp. 809-814, March (2013).
K. Harako, D. Seya, T. Hirooka, and M. Nakazawa, “640 Gbaud (1.28 Tbit/s/ch) optical Nyquist pulse transmission over 525 km with substantial PMD tolerance,” Opt. Express, vol. 21, no. 18, pp.21063-21076, September (2013).
D. O. Otuya, K. Kasai, M. Yoshida, T. Hirooka, and M. Nakazawa, “A single-channel 1.92 Tbit/s, 64 QAM coherent optical pulse transmission over 150 km using frequency-domain equalization,” Opt. Express, vol. 21, no. 19, pp. 22808-22816, September (2013).
K. Koizumi, M. Yoshida, T. Hirooka, and M. Nakazawa, "A single-channel 1.28 Tbit/s-58 km transmission in the 1.1 μm band with wideband GVD and slope compensation," Opt. Express vol. 21, no. 23, pp. 29055-29064, November (2013).
M. Yoshida, T. Hirooka, M. Nakazawa, K. Imamura, R. Sugizaki, and T. Yagi, "Detailed comparison between mode couplings along multi-core fibers and structural irregularities using a synchronous multi-channel OTDR system with a high dynamic range," Opt. Express vol. 21, no. 24, pp. 29157-29164, December (2013).
T. Yajima, J. Yamamoto, F. Ishii, T. Hirooka, M. Yoshida, and M. Nakazawa, "Low-loss photonic crystal fiber fabricated by a slurry casting method," Opt. Express vol. 21, no. 25, pp. 30500-30506, December (2013).
M. Nakazawa, M. Yoshida, T. Hirooka, and K. Kasai, "QAM quantum stream cipher using digital coherent optical transmission," Opt. Express vol. 22, no. 4, pp. 4098-4107, February (2014).
M. Yoshida, T. Hirooka, K. Kasai, and M. Nakazawa, "Adaptive 4~64 QAM real-time coherent optical transmission over 320 km with FPGA-based transmitter and receiver," Opt. Express vol. 22, no. 13, pp. 16520-16527, June (2014).
M. Nakazawa, M. Yoshida, and T. Hirooka, “The Nyquist laser,” Optica vol. 1, no. 1, pp. 15-22, July (2014).
T. Komukai, H. Kubota, T. Sakano, T. Hirooka, and M. Nakazawa, “Plug-and-play optical interconnection using digital coherent technology for resilient network based on movable and deployable ICT resource unit,” IEICE Trans. Comm. vol. E97-B, no. 7, pp. 1334-1341, July (2014).
T. Hirooka, M. Nakazawa, T. Komukai, and T. Sakano, “100 Gbit/s real-time digital coherent transmission over a 32 km legacy multi-mode graded-index fiber,” IEICE Electron. Express vol. 11, no. 15, 20140563, August (2014).
D. O. Otuya, K. Kasai, M. Yoshida, T. Hirooka, and M. Nakazawa, “Single-channel 1.92 Tbit/s, Pol-Mux-64 QAM coherent Nyquist pulse transmission over 150 km with a spectral efficiency of 7.5 bit/s/Hz,” Opt. Express, vol. 22, no. 20, pp. 23776-23785, October (2014).
K. Harako, D. O. Otuya, K. Kasai, T. Hirooka, and M. Nakazawa, “High-performance TDM demultiplexing of coherent Nyquist pulses using time-domain orthogonality,” Opt. Express, vol. 22, no. 24, pp. 29456?29464, December (2014).
M. Nakazawa, M. Yoshida, and T. Hirooka, “Measurement of mode coupling distribution along a few-mode fiber using a synchronous multi-channel OTDR,” Opt. Express, vol. 22, no. 25, pp. 31299-31309, December (2014).
A. Fujisaki, S. Matsushita, K. Kasai, M. Yoshida, T. Hirooka, and M. Nakazawa, “An 11.6 W output, 6 kHz linewidth, single-polarization EDFA-MOPA system with a 13C2H2 frequency stabilized fiber laser,” Opt. Express, vol. 23, no. 2, pp. 1081-1087, January (2015).

Book chapters

M. J. Ablowitz and T. Hirooka, “Quasi-linear optical pulses in dispersion managed fibers: propagation and interaction,” in Optical Solitons: Theoretical and Experimental Challenges, K. Porsezian and V. C. Kuriakose, Eds. (Lecture Notes in Physics 613), Springer-Verlag, 2003, pp. 227-246. [Amazon.com]
M. J. Ablowitz, T. Hirooka, and Z. H. Musslimani, “Nonlinear Waves and (Interesting) Applications,” in Nonlinear Dynamics: From Lasers to Butterflies R. Ball and N. Akhmediev, Eds. (World Scientific Lecture Notes in Complex Systems 1), World Scientific, 2003, pp. 369-410. [Amazon.com]
M. Nakazawa, T. Hirooka, M. Yoshida, and K. Kasai, “Extremely higher-order modulation formats,” Optical Fiber Telecommunications VIB, Chapter 7, pp. 297-336, Springer-Verlag, 2013.