The UG-2 Ring Laser
As a result of the Canterbury Earthquakes the Cashmere Cavern/ Cracroft Caverns Laboratory is currently closed.
UG-2 is the 2nd iteration of an experiment to build an 'ultra large' ring laser. It is an extension to the earlier UG-1 ring (area of 370 square meters) and utilises the maximum possible area of the Cashmere Cavern Laboratory, a rectangle 21 m x 40 m, some 840 square meters. This is easily the largest active ring laser gyro ever constructed. UG-2 was completed in 2005 as an upgrade to the earlier UG-1 ring which first became operation as of September 2000.
The development of the UG series of ring lasers has resulted in much more understanding of the performance limitations of ring lasers, both large and small. Interesting geophysical results have also been obtained, such as our landmark first direct measurement of 'polar wobble', an effect of the moons gravity that causes the Earths rotation axis to be perturbed daily by 60 cm at the poles.
The north arm of the UG-2 laser viewed from the north-west corner.