Herbert H. Gottlieb Low Cost Competition Laser Beam Modulator
Talking into one end of an empty coffee can vibrates a small
mirror that is cemented to a stretched rubber balloon over the
opposite end of the coffee can. A laser pointer is mounted on a
bent curtain rod section so its beam strikes the mirror and is
reflected to a distant screen. Interesting and recognizable
patterns of light can be generated on the screen in response to
any loud sounds entering the coffee can. 1 empty coffee can, top
and bottom removed 1 flat telescoping curtain rod. 1 round
rubber balloon, 5 to 10 cm diameter before inflation 1 piece of
thin front-surface miror, approximately one square 3 rubber
bands 1 laser pointer Rubber cement or a small piece of double-
stick tape. 1. Cut off the neck of your balloon and stretch the
rest of it over an end of your coffee can. Secure it with one or
more rubber 2. Separate the two sections of your flat
telescoping curtain rod. With a hack saw, cut off a length of
approximately 20 centimeters fr