・Remarkable improvement in the temperature characteristics of GaAs lasers using an InGaAlP cladding layer, K. Itaya, G. Hatakoshi, M. Ishikawa, Y. Nishikawa, S. Saito, and M Okajima, IEEE Journal of Quantum Electronics, Vol. 29, No. 6, pp. 2068-2073, 1993

・High-temperature continuous operation above 200 °C of GaAs lasers using an InGaAlP cladding layer, K. Itaya, G. Hatakoshi, Y. Nishikawa, M. Ishikawa and M Okajima, Applied Physics Letters, Vol. 62, No. 18, pp. 2176-2178, 1993

・Current-Voltage Characteristics of p-p Isotype InGaAlP/GaAs Heterojunction with a Large Valence-Band Discontinuity, K. Itaya, M. Ishikawa and G. Hatakoshi, Japanese J. of Applied Physics, Vol. 32, No. 5A, pp. 1919-1922, 1993

・High-brightness InGaAlP green light-emitting diodes, H. Sugawara, K. Itaya, G. Hatakoshi, Applied Physics Letters, Vol. 61, No. 15, pp. 1775-1777, 1992

・High-efficiency InGaAlP visible light-emitting diodes, H. Sugawara, K. Itaya, G. Hatakoshi, Japanese Journal of Applied Physics, Vol. 31, Part 1, No. 8, pp. 2446-2451, 1992

・Reliable high-power (40mW) operation of transverse-mode stabilized InGaAlP laser diodes with strained active layer, K. Nitta, M. Okajima, Y. Nishikawa, K. Itaya, G. Hatakoshi, Electronics Letters, Vol. 28, No. 11, pp. 1069-1070, 1992

・Fifth overtone spectra of C-H stretching vibrations of Pyridine, Pyrazine, and their related compounds, M. Katayama, K. Itaya, T.Nasu, J. Sakai, Journal of Physical Chemistry, Vol. 95, No. 26, pp. 10592-10595, 1991

・Reliable high-power operation of InGaAlP visible light laser diodes with strained active layer, K. Nitta, K. Itaya, Y. Nishikawa, M. Ishikawa, M. Okajima, G. Hatakoshi, Japanese Journal of Applied Physics, Vol. 30, No. 12B, pp. 3862-3864, 1991

・Highly reliable 100mW operation of broad area InGaAlP visible light laser diodes, K. Itaya, N. Shimada, G. Hatakoshi, Electronics Letters, Vol. 27, No. 24, pp. 2257-2258, 1991

・High-temperature operation of high-power InGaAlP visible light laser diodes with an InGaP active layer, K. Nitta, K. Itaya, Y. Nishikawa, M. Ishikawa, M. Okajima, G. Hatakoshi, Applied Physics Letters, Vol. 59, No. 2, pp. 149-151, 1991