To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The sol-gel process is a solution synthesis technique which provides a low temperature chemical route for the preparation of rigid transparent matrices. A number of laser dyes have been incorporated in different sol-gel matrices and tunable laser action has been demonstrated with these materials. This paper extends the sol-gel laser field into two significant areas, infrared dyes and pyrromethenes. The work with the tricarbocyanine dyes shows the versatility of sol-gel chemistry as organic modifications produce a favorable environment for the dye molecules. The results with the pyrromethene system show a considerable increase in output energy and offer the promise of longer laser lifetimes.
Four pyrromethene-BF2 visible laser dyes, dissolved in a MIL-STD tested high temperature polymer matrix and pumped with a doubled Nd:YAG laser produced 61 % slope efficiency and retained 78% of the initial lasing efficiency after 95,000 pulses.
The material and spectroscopic properties of Cr-doped Ca5(PO4)3F (FAP) were investigated using several different chemical and physical means. From analytical titration measurements the chromium in Cr:FAP was found to be tetravalent. ESR measurements detected a trace (0.5 - 10 ppm) of Cr5+ (3d1) and no evidence for Cr3+ (3d3). The absorption and emission spectra of Cr: FAP can be interpreted on the basis of Cr4+ (3d2) ions substituting for P within a distorted tetrahedron of oxygen ions. Calculated electronic (Stark) levels for Cr4+ based on an approximate site symmetry of C4 agree well with levels deduced from an analysis of the experimental optical data. The model Hamiltonian includes Coulombic parameters B and C, interconfiguration interaction terms and the spin-orbit coupling for the 3d2 atomic configuration of Cr4+ and crystal-field terms in C4 symmetry. The parametrized Hamiltonian was diagonalized within the complete d2 configuration. Both free ion and crystal field parameters are presented.
Email your librarian or administrator to recommend adding this to your organisation's collection.