Tsunami - Beckman Institute Laser Resource Center

More documents

Recommendations

Info

Tsunami Signal Interpretation In order to determine the actual pulse width from the displayed autocorrelation function, it is necessary to make an assumption about the pulse shape. Table B-1 shows the relationship between pulse width, A$, and the autocorrelation function, At,,, for several pulse shapes. It also shows the time-bandwidth product, A tp Av, for transform-limited pulses. d Table B-1: Second-order Autocorrelation functions and Time - Bandwidth Products for Various Pulse Shape Models. Function Square Diffraction Function Gaussian Hyperbolic Secant Lorentzian Symmetric twosided exponential 10) I(t) = 1; ltl 5 td2 0; Itl >td2 I(t) = sin2 (ffAtp) (tlAtp) I(t) = exp -(41n2) t2 At2, I(t) = sech2 11.76t) Atp I(t) = 1 1 + (4t2/At2,) I (t) = exp - (ln2)t Atp * At, (sec) is FWHM of intensity envelope of the pulse. ** AhC (sec) is FWHM of autocorrelatorfunction of the pulse. ***At,, (Hertz) is FWHM of the spectrum of the pulse. ** Atp*/~tAC 1 0.751 0.707 0.648 0.500 0.41 3 A~,Av*** 1 0.886 0.441 0.31 5 0.221 0.142
Pulse Width Measurement -% GVD Compensation in Measurement of Ultrashort Pulses Because the pulses produced by the Tsunami laser are extremely short (c 80 fs), the pulse broadening in optical materials from GVD makes measurement of its true pulse width difficult. Also, because the GVD of glass causes the pulse width to broaden, the pulse that reaches an experimental sample after traveling through beam splitters, lenses, etc., may not be the same pulse that is measured in the autocorrelator. It is thus important to ensure that the measurement technique and experimental set up incorporate the same amount of glass and some GVD compensation if the shortest pulses are to be measured and delivered to a sample. Even before the pulse leaves the laser, it travels through extra glass. For example, if we assume the pulse in a Tsunami laser is at its shortest as it passes through the coating of the output coupler, it then travels through the output coupler substrate, the photodiode beam splitter and the output window. For the Tsunami laser, the total thickness of these optics is about 1.9 cm (0.75 in.). Thus, a pulse that is 60 fs at the output coupler coating becomes 66 fs by the time it exits the laser. Include the glass of the autocorrelator and that in any experimental setup and the pulse can be broadened substantially. Since most autocorrelators use beam splitters, a lens, and often a spinning block (as in the Model 409 -08), the pulse is also broadened before it is measured. This means the pulse out of the Tsunami may be actually shorter than that indicated by direct measurement. Consequently, GVD must also be compensated when using an autocorrelator. Since the sign of GVD in material is generally positive for the wavelengths produced by the Tsunami laser, introducing negative GVD into the beam path compensates for the broadening effect of the material. Negative GVD can be introduced into a system with prism pairs, grating pairs, or a Gires- Tournois Interferometer (GTI). The prism pair provides the easiest, lowest loss means for compensating for the positive GVD of materials. To compensate for pulse broadening from materials, a simple setup using two high index prisms (SF-10) is all that is necessary. Figure B-4 shows the layout (top and side views) for an easily built pre-compensation unit. The laser pulse travels through the first prism where different frequency components are spread in space. Then the broadened pulse travels through the second prism, strikes a high reflector, and reflects back along its original path-with one exception. The high reflector is slightly tilted in the plane perpendicular to the spectral spreading and causes the pulse to travel back through the prisms at a slightly different vertical height. After the beam returns through the first prism it is reflected by another mirror to the autocorrelator andlor the experiment.
Page 1:
Tsunami Mode-locked Ti: sapphire La
Page 5 and 6:
Table of Contents ... Preface .....
Page 7 and 8:
Table of Contents . Chapter 6: Alig
Page 9 and 10:
Table of Contents Chapter 10: Optio
Page 11 and 12:
Table of Contents Figure 4-7: Typic
Page 13 and 14:
Table of Contents Figure A-6: The f
Page 15:
Warning Conventions The following w
Page 19:
List of Abbreviations Used in this
Page 22 and 23:
Tsunami Figure 1-1: The Tsunami Las
Page 25 and 26:
Chapter 2 Laser Safety DANGER The T
Page 27 and 28:
Laser Safety CA UTlON Use of contro
Page 29 and 30:
1 1 1 Il I 11 I I 1 El l11111II~Ill
Page 31 and 32:
Chapter 3 Laser Description General
Page 33 and 34:
Laser Description growth techniques
Page 35 and 36:
Laser Description - AOM OC n Fast P
Page 37 and 38:
Laser Description 2.4 - 2.2 - 2.0 -
Page 39 and 40:
I IIIIIN III I I 1 I 11111 i~ I I I
Page 41 and 42:
I II li I I I i 1 il I 1 11 I 1 1 1
Page 43:
I Laser Description . Outline Dimen
Page 46 and 47:
Tsunami Input Bezel Connections The
Page 48 and 49:
Tsunami Opto-Mechanical Controls Al
Page 50 and 51:
Tsunami Blue Knob: Vertical Adjust
Page 52 and 53:
~lpl~ f \ Tsunami Opto-Mechanical C
Page 54 and 55:
Tsunami Figure 4-7: 'Qpical MONITOR
Page 56 and 57:
Tsunami r @ Spectra-Physics - - 4 2
Page 58 and 59:
Tsunami Laser Installation Installi
Page 60 and 61:
Tsunami Setting up the Routing Mirr
Page 62 and 63:
Tsunami Aligning the Tsunami Laser
Page 64 and 65:
Tsunami A -----------. PHOTODIODE O
Page 66 and 67:
Tsunami Removing the Purge Line fro
Page 68 and 69:
Tsunami Motorized Mount "Dm-shaped
Page 70 and 71:
Tsunami I I J3 3930 - - - #,-,I --J
Page 72 and 73:
Tsunami CA UTION DO NOT remove or a
Page 74 and 75:
Tsunami Refer to the tables at the
Page 76 and 77:
Tsunami b. Move the stage by hand a
Page 78 and 79:
Tsunami There will be one or two re
Page 80 and 81:
Tsunami Figure 6-9: The Slit Contro
Page 82 and 83:
Tsunami b. Place a white card with
Page 84 and 85:
Tsunami Aligning the Photodiode PC
Page 86 and 87:
Tsunami To measure pulses, use a Sp
Page 88 and 89:
Tsunami pulses, adjust the coarse c
Page 90 and 91:
Tsunami Selecting, Installing, and
Page 92 and 93:
Tsunami Unless you are certain the
Page 94 and 95:
Tsunami Prism Translation Adjust Fi
Page 96 and 97:
Tsunami i. Route the GTI heater cab
Page 98 and 99:
Tsunami Figure 6-18: Pr1/Pr4 prisms
Page 100 and 101:
Tsunami Converting Between fs and p
Page 102 and 103:
Tsunami b. Using an ir viewer, adju
Page 104 and 105:
Tsunami g. Open the shutter. 15. Al
Page 106 and 107:
Tsunami 10. Move Prl and Pr4 into t
Page 108 and 109:
Tsunami 21. Mode lock Tsunami. Refe
Page 110 and 111:
I " n 3 1 ' ! ' I . I 8 8 8 " t 8 0
Page 112 and 113:
Tsunami recommend using 99.999% pur
Page 114 and 115:
Tsunami Mode Locking the Laser 6. W
Page 116 and 117:
Tsunami - - - 710 nrn - - 790 nrn -
Page 118 and 119:
4 Tsunami Beam % 2 mm (0.08 in.) Pr
Page 120 and 121:
Tsunami Table 7-1: Bi-fi Selection
Page 123 and 124:
I I1 ! I : I I I ill 8 I !Il! I1I l
Page 125 and 126:
Lok-to-Clock Electronics LEVEL cont
Page 127 and 128:
Lok-to-Clock Electronics AOM M5f-4
Page 129 and 130:
Lok-to-Clock Electronics Installing
Page 131 and 132:
I I1 I i l l I iil 111 ,111 Ill ,il
Page 133 and 134:
P Lok-to-Clock Electronics Model 20
Page 135 and 136:
I 1 1 I 1~~~ 11 I 1 1 1 1 .III :ill
Page 137 and 138:
Lok-to-Clock Electronics Figure 8-9
Page 139:
I I1 I l I 1 bll Lok-to-Clock Elect
Page 142 and 143:
Tsunami "Clean" is a relative descr
Page 144 and 145: Tsunami Figure 9-1: Drop and Drag M
Page 146 and 147: Tsunami With the exception of pump
Page 148 and 149: Tsunami On rare occasions, the lowe
Page 150 and 151: Tsunami 8. Open the pump laser shut
Page 152 and 153: Tsunami 7. Remove the screws (4) ho
Page 154 and 155: Tsunami DryJClean Flow Adjust Nitro
Page 156 and 157: Tsunami diode such as the Model 393
Page 158 and 159: €968-PEP0 ES68-PEP0 PS68-PEP0 ES6
Page 160 and 161: Tsunami Check marks indicate which
Page 162 and 163: Tsunami Table 10-11: GTI and Bi-Pi
Page 164 and 165: Tsunami Generic Troubleshooting (No
Page 166 and 167: Tsunami Symptom: Laser will not mod
Page 168 and 169: Tsunami Symptom: Unable to mode loc
Page 170 and 171: Tsunami Symptom: Unable to mode loc
Page 172 and 173: Tsunami Symptom: Cannot see individ
Page 174 and 175: Tsunami Symptom: PZT oscillates whe
Page 177 and 178: I I ill ; I l l I I lll.l1 I I I *
Page 179 and 180: I I 111 il I iil i lllill ll I I ll
Page 181 and 182: I I il : I I I 1 I Appendix A Mode
Page 183 and 184: Mode Locking is chosen to be the sa
Page 185 and 186: I I 0 I I 1 I )I Ulllllll ill I Mod
Page 187 and 188: Mode Locking SPM will, thus, broade
Page 189 and 190: Mode Locking The net intracavity GV
Page 191 and 192: Appendix B Pulse Width Measurement
Page 193: I I 0 I I 1 1 LI I lillll Ill I!,ll
Page 197 and 198: I I I I I I I I ti 911 I1 I Pulse W
Page 199 and 200: I I I I I I B I IL 1 1 i 1111 I L I
Page 201 and 202: I I 0 I I 1 1 L I I Pulse Width Mea
Page 203 and 204: Appendix C Setting the Line Voltage
Page 205 and 206: Appendix D Material Safetv Data She
Page 207 and 208: Material Safety Data Sheets MATERIA
Page 209 and 210: I I I 1 r $1 I Bill II I I I I Ill
Page 211 and 212: Material Safety Data Sheets MATERIA
show all

Tsunami - Beckman Institute Laser Resource Center

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?