Summers, H., Smowton, P., Lewis, G., Yin, M., Summers, H., Berry, G., & Button, C. (1999). 650-nm lasers with narrow far-field divergence with integrated optical mode expansion layers. IEEE Journal of Selected Topics in Quantum Electronics, 5(3), pp. 735-739. doi:10.1109/2944.788444

Summers, Huw, P.M Smowton, G.M Lewis, M. Yin, H.D Summers, G. Berry, and C.C Button. "650-nm Lasers With Narrow Far-field Divergence With Integrated Optical Mode Expansion Layers." IEEE Journal of Selected Topics in Quantum Electronics 5, no. 3 (1999): 735-739.

Summers, Huw, et al. "650-nm Lasers With Narrow Far-field Divergence With Integrated Optical Mode Expansion Layers." IEEE Journal of Selected Topics in Quantum Electronics 5.3 (1999): 735-739.