1. Daniel Frank Walls FRS was a New Zealand theoretical physicist specialising in quantum optics.

1. Daniel Frank Walls FRS was a New Zealand theoretical physicist specialising in quantum optics.
Dan Walls then went to Harvard University as a Fulbright Scholar, obtaining his PhD in 1969.
Dan Walls was supervised by Roy J Glauber who was later awarded a Nobel prize in 2005.
Dan Walls was notable for his wide-ranging expertise in relating theory to experiment, and was involved in all major efforts to understand non-classical light.
Dan Walls was a pioneer in the study of ways that the particle-like nature of light could be controlled to make optical systems less susceptible to unwanted fluctuations, in particular by the use of squeezed light, a concept formulated by Carlton Caves.
Dan Walls made major contributions to the theory of quantum measurement such as those involving Albert Einstein's"which-path" experiment, and the quantum nondemolition measurement.
Dan Walls was elected a Fellow of the Royal Society in 1992.
Dan Walls was elected Fellow of the American Physical Society and the Royal Society of New Zealand.
Dan Walls had two younger siblings, a sister and a brother.
Dan Walls married Fari Khoy in 1968 with whom he had one son, Mark, in 1980.
Dan Walls died of cancer at hospital, in Auckland, aged 57.