High-order achromatic quarterwave combination plates and tuners.
Achromatic quarterwave combination plates are formed from two high-order birefringent plates having even and odd multiples of quarterwave retardation at some nominal wavelength. Eleventh- and twelfth-order plates at 1315 nm combined with their axes 77 degrees apart are shown to have 90 +/- 0.25 degrees of retardation between 1275 and 1355 nm. They can be used to construct two- and four-waveplate tuners for birefringent filters.
Four waveplate dual tuner for birefringent filters and multiplexers.
A Solc-type birefringent filter with five crystal elements in a wavelength multiplexer configuration is tuned with a minimum number of waveplates by means of a new four waveplate dual tuner that adds equal retardations to two elements simultaneously.
Magnetic plasma confinement for laser ion source.
A laser ion source (LIS) can easily provide a high current beam. However, it has been difficult to obtain a longer beam pulse while keeping a high current. On occasion, longer beam pulses are required by certain applications. For example, more than 10 micros of beam pulse is required for injecting highly charged beams to a large sized synchrotron. To extend beam pulse width, a solenoid field was applied at the drift space of the LIS at Brookhaven National Laboratory. The solenoid field suppressed the diverging angle of the expanding plasma and the beam pulse was widened. Also, it was observed that the plasma state was conserved after passing through a few hundred gauss of the 480 mm length solenoid field.