13 In these measurements the uncertainties were typically limited by signal-to-noise ratio and fitting uncertainties combined with uncertainties in the determination of the ac Stark shifts and geometrical factors. cw laser spectroscopy techniques and demonstrates the versatility of direct frequency comb spectroscopy. Our measured transition frequencies are in good agreement with previous measurements, while achieving greater accuracy for the 9S$_{1}$$_{/}$$_{2}$ , 7D$_{3}$$_{/}$$_{2}$ , and 7D$_{5}$$_{/}$$_{2}$ states. We thank Hugh Robinson for insightful advice and preparation of the Cs vapor cell. We are grateful to Jose Almaguer, Nate Newbury, and Todd Johnson for care- fully reading the manuscript and providing valuable sug- gestions and discussions. One of us (VM) was supported in part by the DST(RSA) PDP through the National VI. ACKNOWLEDGEMENTS Measurement Center-of-Gravity Frequency Hyperfine Constant A Hyperfine Constant B 8S 1 / 2 This Work 729 009 798 . 86(19) 219.14(11) - Fendel et al. [22] 729 009 799 . 020(26) 219.125(4) - Hagel et al. [21] 729 009 798 . 82(20) 219.12(1) - 9S 1 / 2 This Work 806 761 363 . 38(19) 109.93(9) - Weber & Sansonetti [23] 806 761 372(8) - - Farley et al. [29] - 110.1(5) - Gupta et al. [30] - 109.5(2.0) - 7D 3 / 2 This Work 780 894 762 . 250(77) 7.386(15) -0.18(16) Weber & Sansonetti [23] 780 894 772(8) - - Kortyna et al. [31] - 7.36(3) -0.1(2) Auzinsh et al. [32] - 7.4(2) - 7D 5 / 2 This Work 781 522 153 . 68(10) -1.717(15) -0.18(52) Weber & Sansonetti [23] 781 522 153(8) - - Auzinsh et al. [32] - -1.56(9) - Effect ν $^{6S$_{1}$}$/ $^{$_{2}$:8S$_{1}$}$/2 A $^{8S$_{1}$}$/ 2 ν $^{6S$_{1}$}$/ $^{$_{2}$:9S$_{1}$}$/2 A $^{9S$_{1}$}$/ 2 ν $^{6S$_{1}$}$/ $^{$_{2}$:7D$_{3}$}$/2 A $^{7D$_{3}$}$/ 2 B $^{7D$_{3}$}$/ 2 ν $^{6S$_{1}$}$/ $^{$_{2}$:7D$_{5}$}$/2 A $^{7D$_{5}$}$/ 2 B $^{7D$_{5}$}$/ 2 ac Stark 166 94 169 79 49 14 17 85 11 458 B-Field 70 40 18 7 17 3 17 35 6 125 Cs Vapor Pressure 31 18 34 15 12 1 26 7 1 38 Alignment 22 20 58 20 48 12 143 34 7 180 Overlap of 7D 3 / 2 - - - - - - - 9 1 30 Statistical 24 13 58 30 28 20 72 25 4 86 Total 186 106 192 88 77 15 164 102 15 517 TABLE I: Summary of the contributions to the error budget for the measured transition frequencies and hyperfine constants. All frequencies are given in kilohertz. TABLE II: Comparison of the center-of-gravity frequencies and hyperfine coupling constants measured in this work with previous measurements. All numbers are in megahertz. The uncertainties represent the standard error (68% confidence interval).