K. Maru, T. Mizumoto, H. Uetsuka, "Modeling of multi-input arrayed waveguide grating and its application to design of flat-passband
response using cascaded Mach–Zehnder interferometers," J. Lightw. Technol. 25, 544-555 (2007).

K. Maru, M. Okawa, Y. Abe, T. Hakuta, S. Himi, H. Uetsuka, "Silica-based 2.5%-$\Delta$ arrayed waveguide grating using
simple polarisation compensation method with core width adjustment," Electron. Lett. 43, 26-27 (2007).

K. Maru, T. Hakuta, Y. Abe, M. Ito, S. Himi, H. Uetsuka, T. Mizumoto, "Spot-size converter using vertical ridge taper for low fiber-coupling loss in 2.5%-$\Delta$ silica waveguides," Electron. Lett. 42, 219-220 (2006).

C. R. Doerr, M. A. Cappuzzo, E. Y. Chen, A. Wong-Foy, L. T. Gomez, L. L. Buhl, "Wideband arrayed waveguide grating with three low-loss maxima per passband," IEEE Photon. Technol. Lett. 18, 2308-2310 (2006).

C. R. Doerr, M. A. Cappuzzo, E. Y. Chen, A. Wong-Foy, L. T. Gomez, "Low-loss rectangular-passband multiplexer consisting of a waveguide grating router synchronized to
a three-arm interferometer," IEEE Photon. Technol. Lett. 17, 2334-2336 (2005).

K. Maru, Y. Abe, M. Ito, H. Ishikawa, S. Himi, H. Uetsuka, T. Mizumoto, "2.5%-$\Delta$ silica-based athermal arrayed waveguide
grating employing spot-size converters based on segmented core," IEEE Photon. Technol. Lett. 17, 2325-2327 (2005).

T. Mizuno, T. Kitoh, M. Itoh, T. Saida, T. Shibata, Y. Hibino, "Optical spotsize converter using narrow laterally tapered waveguide for planar lightwave circuits
," J. Lightw. Technol. 22, 833-839 (2004).

C. R. Doerr, R. Pafchek, L. W. Stulz, "Integrated band demultiplexer using waveguide grating routers," IEEE Photon. Technol. Lett. 15, 1088-1090 (2003).

C. R. Doerr, L. W. Stulz, R. Pafchek, S. Shunk, "Compact and low-loss manner of waveguide grating router passband flattening and demonstration in a
64-channel blocker/multiplexer," IEEE Photon. Technol. Lett. 14, 56-58 (2002).

C. Dragone, "Theory of wavelength multiplexing with rectangular transfer functions," IEEE J. Sel. Topics Quantum Electron. 8, 1168-1178 (2002).

M. Itoh, T. Saida, Y. Hida, M. Ishii, Y. Inoue, Y. Hibino, A. Sugita, "Large reduction of singlemode-fibre coupling loss in 1.5%$\Delta$ planar lightwave circuits using spot-size converters," Electron. Lett. 38, 72-73 (2002).

P. Muñoz, D. Pastor, J. Capmany, "Modeling and design of arrayed waveguide gratings," J. Lightw. Technol. 20, 661-674 (2002).

C. R. Doerr, M. Cappuzzo, E. Laskowski, A. Paunescu, L. Gomez, L. W. Stulz, J. Gates, "Dynamic wavelength equalizer in silica using the single-filtered-arm interferometer
," IEEE Photon. Technol. Lett. 11, 581-583 (1999).

C. Dragone, "Efficient techniques for widening the passband of a wavelength router," J. Lightw. Technol. 16, 1895-1906 (1998).

M. Kawachi, "Silica waveguides on silicon and their application to integrated-optic components," Opt. Quantum Electron. 22, 391-416 (1990).

C. Dragone, "Efficient $N \times N$ star couplers using Fourier optics
," J. Lightw. Technol. 7, 479-489 (1989).

N. Takato, K. Jinguji, M. Yasu, H. Toba, M. Kawachi, "Silica-based single-mode waveguides on silicon and their application to guided-wave optical
interferometers," J. Lightw. Technol. 6, 1003-1010 (1988).

B. H. Verbeek, C. H. Henry, N. A. Olsson, K. J. Orlowsky, R. F. Kazarinov, B. H. Johnson, "Integrated four-channel Mach–Zehnder multi/demultiplexer fabricated with phosphorous doped
$\hbox{SiO}_{2}$ waveguides on Si," J. Lightw. Technol. 6, 1011-1015 (1988).

A. Yariv, "Coupled-mode theory for guided-wave optics," IEEE J. Quantum Electron. QE-9, 919-933 (1973).

M. Itoh, T. Saida, Y. Hida, M. Ishii, Y. Inoue, Y. Hibino, A. Sugita, "Large reduction of singlemode-fibre coupling loss in 1.5%$\Delta$ planar lightwave circuits using spot-size converters," Electron. Lett. 38, 72-73 (2002).

K. Maru, T. Hakuta, Y. Abe, M. Ito, S. Himi, H. Uetsuka, T. Mizumoto, "Spot-size converter using vertical ridge taper for low fiber-coupling loss in 2.5%-$\Delta$ silica waveguides," Electron. Lett. 42, 219-220 (2006).

K. Maru, M. Okawa, Y. Abe, T. Hakuta, S. Himi, H. Uetsuka, "Silica-based 2.5%-$\Delta$ arrayed waveguide grating using
simple polarisation compensation method with core width adjustment," Electron. Lett. 43, 26-27 (2007).

A. Yariv, "Coupled-mode theory for guided-wave optics," IEEE J. Quantum Electron. QE-9, 919-933 (1973).

C. Dragone, "Theory of wavelength multiplexing with rectangular transfer functions," IEEE J. Sel. Topics Quantum Electron. 8, 1168-1178 (2002).

C. R. Doerr, R. Pafchek, L. W. Stulz, "Integrated band demultiplexer using waveguide grating routers," IEEE Photon. Technol. Lett. 15, 1088-1090 (2003).

C. R. Doerr, M. A. Cappuzzo, E. Y. Chen, A. Wong-Foy, L. T. Gomez, "Low-loss rectangular-passband multiplexer consisting of a waveguide grating router synchronized to
a three-arm interferometer," IEEE Photon. Technol. Lett. 17, 2334-2336 (2005).

C. R. Doerr, M. A. Cappuzzo, E. Y. Chen, A. Wong-Foy, L. T. Gomez, L. L. Buhl, "Wideband arrayed waveguide grating with three low-loss maxima per passband," IEEE Photon. Technol. Lett. 18, 2308-2310 (2006).

K. Maru, Y. Abe, M. Ito, H. Ishikawa, S. Himi, H. Uetsuka, T. Mizumoto, "2.5%-$\Delta$ silica-based athermal arrayed waveguide
grating employing spot-size converters based on segmented core," IEEE Photon. Technol. Lett. 17, 2325-2327 (2005).

C. R. Doerr, M. Cappuzzo, E. Laskowski, A. Paunescu, L. Gomez, L. W. Stulz, J. Gates, "Dynamic wavelength equalizer in silica using the single-filtered-arm interferometer
," IEEE Photon. Technol. Lett. 11, 581-583 (1999).

C. R. Doerr, L. W. Stulz, R. Pafchek, S. Shunk, "Compact and low-loss manner of waveguide grating router passband flattening and demonstration in a
64-channel blocker/multiplexer," IEEE Photon. Technol. Lett. 14, 56-58 (2002).

T. Mizuno, T. Kitoh, M. Itoh, T. Saida, T. Shibata, Y. Hibino, "Optical spotsize converter using narrow laterally tapered waveguide for planar lightwave circuits
," J. Lightw. Technol. 22, 833-839 (2004).

N. Takato, K. Jinguji, M. Yasu, H. Toba, M. Kawachi, "Silica-based single-mode waveguides on silicon and their application to guided-wave optical
interferometers," J. Lightw. Technol. 6, 1003-1010 (1988).

B. H. Verbeek, C. H. Henry, N. A. Olsson, K. J. Orlowsky, R. F. Kazarinov, B. H. Johnson, "Integrated four-channel Mach–Zehnder multi/demultiplexer fabricated with phosphorous doped
$\hbox{SiO}_{2}$ waveguides on Si," J. Lightw. Technol. 6, 1011-1015 (1988).

P. Muñoz, D. Pastor, J. Capmany, "Modeling and design of arrayed waveguide gratings," J. Lightw. Technol. 20, 661-674 (2002).

K. Maru, T. Mizumoto, H. Uetsuka, "Modeling of multi-input arrayed waveguide grating and its application to design of flat-passband
response using cascaded Mach–Zehnder interferometers," J. Lightw. Technol. 25, 544-555 (2007).

C. Dragone, "Efficient techniques for widening the passband of a wavelength router," J. Lightw. Technol. 16, 1895-1906 (1998).

C. Dragone, "Efficient $N \times N$ star couplers using Fourier optics
," J. Lightw. Technol. 7, 479-489 (1989).

M. Kawachi, "Silica waveguides on silicon and their application to integrated-optic components," Opt. Quantum Electron. 22, 391-416 (1990).

Y. Hibino, Y. Hida, A. Kaneko, M. Ishii, M. Itoh, T. Goh, A. Sugita, T. Saida, A. Himeno, Y. Ohmori, "Fabrication of silica-on-Si waveguide with higher index difference and its application to 256
channel arrayed-waveguide multi/demultiplexer," Proc. OFC (2000) pp. 127-129.

T. Shimoda, K. Suzuki, S. Takaesu, M. Horie, A. Furukawa, "A low-loss, compact wide-FSR-AWG using SiON planar lightwave circuit technology," Proc. OFC (2003) pp. 703.

K. Maru, H. Ishikawa, H. Komano, N. Kitano, Y. Abe, K. Matsui, S. Kashimura, S. Himi, H. Uetsuka, "2.5%-$\Delta$ silica-based arrayed-waveguide grating
multi/demultiplexer with low crosstalk," Proc. OECC/COIN (2004) pp. 720-721.

C. K. Madsen, J. H. Zhao, Optical Filter Design and Analysis (Wiley, 1999) pp. 171-177.

H. Dym, H. P. McKean, Fourier Series and Integrals (Academic, 1972) pp. 31-32.

C. Dragone, Frequency routing device having a wide and substantially flat passband U.S. Patent 5 488 680 (1996).

G. H. B. Thompson, R. Epworth, C. Rogers, S. Day, S. Ojha, "An original low-loss and pass-band flattened $\hbox{SiO}_{2}$
on Si planar wavelength demultiplexer," Proc. OFC (1998) pp. 77.

K. Maru, T. Mizumoto, H. Uetsuka, "Flat-passband arrayed waveguide grating employing cascaded Mach–Zehnder interferometers
," OptoElectronics Commun. Conf. (OECC) KaohsiungTaiwan, R.O.C. (2006) Paper 5B2-5.

I. Kaminow, T. Li, Optical Fiber Telecommunications IVA (Academic, 2002) pp. 424-427.

Y. Inoue, M. Itoh, Y. Hashizume, Y. Hibino, A. Sugita, A. Himeno, "Novel birefringence compensating AWG design," Optical Fiber Commun. Conf. (OFC) AnaheimCA (2001) Paper WB4.