Multiwavelength interferometry system for the Orion laser facility

Abstract

We report on the design and testing of a multiwavelength interferometry system for the Orion laser facility based upon the use of self-path matching Wollaston prisms. The use of UV corrected achromatic optics allows for both easy alignment with an eye-safe light source and small (∼ millimeter) offsets to the focal lengths between different operational wavelengths. Interferograms are demonstrated at wavelengths corresponding to first, second, and fourth harmonics of a 1054 nm Nd:glass probe beam. Example data confirms the broadband achromatic capability of the imaging system with operation from the UV (263 nm) to visible (527 nm) and demonstrates that features as small as 5 μm can be resolved for object sizes of 15 by 10 mm. Results are also shown for an off-harmonic wavelength that will underpin a future capability. The primary optics package is accommodated inside the footprint of a ten-inch manipulator to allow the system to be deployed from a multitude of viewing angles inside the 4 m diameter Orion target chamber.

A history of high-power laser research and development in the United Kingdom

“…The front-end architecture of Cerberus is by a combination of design and 'convergent evolution' very similar to that of the Orion laser at AWE, allowing this system to be used for proof of principle laser and diagnostic development for Orion. It has also been used to develop new plasma diagnostic systems such as multi-wavelength imaging interferometry [77] and high-brightness broad-band light sources [78] for Orion, a facility also accessed by members of the Plasma Physics Group for experiments in areas such as radiative astrophysical shock studies [79] .…”

Optical probing of high intensity laser interaction with micron-sized cryogenic hydrogen jets

“…Typically, the probe pulse is split from the driver after compression very close to the laser plasma interaction region in order to provide intrinsic temporal synchronization at lowest timing jitter and minimal technical effort. The probe pulses or its higher harmonics [12] are then used to transversely illuminate the laser target interaction and to characterize the spatio-temporal plasma conditions by applying different techniques such as shadowgraphy [13,14] or interferometric schemes [15][16][17][18] to reconstruct the plasma density profile or to estimate the magnetic field distribution via polarimetry. Other methods rely on the reflection of the probe beam at the critical density surface [19][20][21][22].…”