Pulsed and CW laser experiments in cesium and sodium-potassium vapors: The velocity dependence of 5DJ + 6PJ' going to DJ" + 6S1/2 energy pooling collisions in cesium vapor and absolute transition dipole moments of sodium-potassium 3(1)pi going to X(1)sigma+ and 3(1)pi going to A(1)sigma+ transitions using Autler-Townes spectroscopy.

Description

The first part of this dissertation will describe a study of the velocity dependence of the cesium 5DJ +6P J' → 7DJ" +6S 1/2 energy pooling process using molecular photolysis. Fast Cs(5 D) atoms with well defined velocities are created via the molecular photodissociation process Cs2 +hnu → Cs(6 S)+Cs(5D)+DeltaE. The speed of the fast atoms is controlled by the frequency of the pulsed photolysis laser, while a thermal population of Cs(6P) atoms is created using cw laser. We then measure the 7D → 6P fluorescence in the early time after the photolysis pulse before the 5 D atoms are able to thermalize. We normalize the relative energy pooling rate coefficient found at this early time at various pulsed laser frequencies to the energy pooling rate coefficient measured at a later time when the fast atoms will have undergone thermalizing collisions. Our results indicate that a velocity dependence does exist for both the 5D J + 6P3/2 → 7D J" + 6S1/2 and 5D J +6 P1/2 → 7D J" + 6S1/2 energy pooling processes, proving the viability of this technique for further studies the velocity dependences of atomic collision processes.In the second part of this dissertation, a two-laser experiment using OODR and Autler-Townes splittings to determine NaK 31pi → X1Sigma+, A 1Sigma+ absolute transition dipole moment functions is described. Resolved 31pi → A 1Sigma+ and 31pi → X1Sigma+ fluorescence is recorded with the frequencies of a Ti:Sapphire laser (L1) and a ring dye laser (L2) fixed to excite particular 31pi(19,11,f) ← A1Sigma+(nu',11,e) ← X1Sigma+(nu", J +/- 1,e) transitions. The coefficients of a trial transition dipole moment function mu(R) = a 0 + a1R-2 + a2R-4 +... are adjusted to match the relative intensities of resolved spectral lines terminating on A1Sigma+ (nu',11 ,e) and X1Sigma+ (nu",11,e) levels. These data provide a relative measure of the function mue( R) over a broad range of R. Next, L2 is tuned to the specific 31pi(19,11,f) ← A1Sigma+(10,11,e) and 31pi(19,11,f) ← A 1Sigma+(9,11,e) transitions and focused to an intensity large enough to split the levels via the Autler-Townes effect. L1 is scanned over the A1Sigma +(10,11,e) ← X1Sigma +(1,J+/-1,e) and A 1Sigma+ (9,11,e) ← X1Sigma+(1,J+/-1, e) transitions, in turn, to probe the AT lineshape, which is fit using density matrix equations to yield absolute values for [vertical bar]〈31pi(19,11,f)[vertical bar]mu( R)[vertical bar]A1Sigma+(10,11, e)〉[vertical bar] and [vertical bar]〈31pi(19,11,f)[vertical bar]mu( R)[vertical bar]A1Sigma+(9,11, e)〉[vertical bar]. This value is used to place the relative mu e (R) obtained with resolved fluorescence onto an absolute scale. For the 31pi → A 1Sigma+ transition, we find mabse,3→A = 10.7 -- 5.38 (Req/R)2, whereas for the 31pi → X1Sigma + transition, we find mabse,3→X = 3.29(Req/R)2 -- 10.7(Req/R)4 +11.9(R eq/R)6 -- 3.76(Req/R )8, both of which are given in Debye.  Read more...