Page 222 - Tunable Lasers Handbook

198 F. J. Duarte

TABLE 18 Matrices for Solid-state Dye Lasers
~~ ~~~~
Matrix Abbreviation

Poll methyl methacrylaten PMM4
Modified polymethyl methacrylare MPMMA
Tetraethoxysilane [Si(OCIH,),] TEOS
Tetramethoxysilane [Si(OCH3),] TMOS
Organically modified silicate ORMOSIL
Silica-PMMA nanocotnposites

Nethyl methacrylate (MMA) is CH,= C(CH,)COOCH,.

these experiments was 2 mM and the excitation laser was a flashlamp-pumped
dye laser with a 170-11s pulse duration [45].
An alternative to ORMOSILs are the transparent silica-PMMA nanocom-
posites [ 1461. Although these nanocomposites have a number of similarities with
ORMOSILs, including very high transparencies, they also have a number of syn-
thetic differences [ 1461. These nanocomposites can be optically polished to yield
high-quality optical surfaces. This feature. coupled to their high transparency.
offers a very attractive optical material. Silica-PMMA nanocomposites doped
with rhodamine 6G and rhodamine B have been made to lase under transverse
excitation from a coumarin 152 dye laser [147].
An important difference between PMMA-type matrices and silicate matrices
is the internal structure of the latter. This structure can induce refractive index
variations that leads to optical inhomogeneities of the active medium. These
inhomogeneities can be characterized by propagating a narrow-linewidth laser
through the matrix and then observing the far-field interferometric pattern thus
produced [ 1471.
The energetic and efficiency performances of solid-state dye lasers using a
variety of host matrices are listed in Table 19.
The performance of solid-state dispersive dye laser oscillators is given in
Chapter 2 for MPMMA matrices. In addition to those results, Duarte et al. [45]
reports an output energy of - 1 mJ at Av = 3 GHz for a multiple-prism grating
oscillator using TEOS doped with rhodamine 6G at 2 mM. The same oscillator
yielded <1 mJ/pulse for ORMOSIL doped with rhodamine 6G at the same con-
centration. In an extension of the work published in 1461. Duarte [I531 has opti-
mized the architecture of the solid-state multiple-prism grating dye laser oscilla-
tors and has demonstrated a very compact dispersive oscillator. This dispersive
oscillator has a cavity length in the 55-60 mm range and yields efficient single-
longitudinal-mode lasing at AV = 320 MHz with a near-Gaussian temporal pro-
file 34 ns in duration (FWHM).