injector lasers overview sasha gilevich, slac april 29, 2004

1

Injector Lasers OverviewSasha Gilevich, SLAC

April 29, 2004

Drive Laser SpecificationsChallengesSystem DescriptionLaser ProcurementR&D EffortUV conversion

Lasers Overview

04/29/2004 Sasha Gilevich

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2

Sector 20 LaserLaser Bay

Transport Tube

UV Launch and Condition.

Accelerators

Lasers Overview


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Laser Heater

Drive Laser

RF Gun

10 m

3

Laser Bay

Lasers Overview


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4

UV Beam Specifications at Photocathode

Parameter Nominal spec Tolerance

Energetic: wavelength 255nm nom. + < 5 nm

- 0 nm

pulse energy

> 0.20 mJ

(for 1 nC production with 3x10-5 QE)

< 2 % rms variation

Spatial: fluence profile

Uniform (nom.) (adjustable)

< 20 %

(peak-to-peak)

spot radius 1.2 mm < 4 %

(shot-to-shot)

centroid position

< 10 % radius

(RMS over multiple shots)

Lasers Overview


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5

UV Beam Specifications at Photocathode (cont.)


Temporal: rep rate 120 Hz

power profile Uniform

(adjustable plateau slope)

< 5%

(RMS noise on the plateau)

profile FWHM 10 psec

adjustable to 20 psec

< 2 % RMS

(over multiple shots)

profile rise/fall times

1.0 psec (10% - 90%)

timing jitter (with respect to RF)

< 0.5 psec

(shot-to-shot)

Lasers Overview


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Sasha Gilevich

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6

ChallengesShort rise/fall timeRequires temporal pulse shaping

ReliabilityThe system should operate 24x7

Pumping systemLife time of the flash lamp – about 300-500h => Changing Lamps Every ~2wksLaser Diode Lifetime ~ 10000hrChanging Diodes Every ~ 60 wks (~1 yr)

UV conversion unit Shaping hardware

Automatic Operation

Lasers Overview


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Input pulse

0

0.2

0.4

0.6

0.8

1

-15 -10 -5 0 5 10 15

Time, psec

Nor

m. P

ower

Non shaped

Shaped

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Losses Component Efficiency

UV Conversion Unit 8 - 12%

Dichroic Separation 90 - 95%

UV Pulse Energy Control 85 - 95%

Spatial Filter, Telescope, Collimator Flattener 70 - 80%

Relay System to UV Launch Table (through vertical transport tube) 60 – 80%

UV Launch Optics to Grating 80 – 90%

UV Launch Grating 45 – 55%

Final Trimmer 70 – 80%

UV Waveplate, Vacuum Window 90 -96%

Net Transport and UV Conversion Efficiency – 0.7 – 2.1%

Lasers Overview


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8

Drive IR Laser Specifications


Energetic: wavelength 765 nm (10 nm bandwidth)

+ < 15 nm

- 0 nm

pulse energy > 25 mJ (1 nC production with 3X10-5 QE)

< 1 % rms variation


Spatial: fluence profile Uniform (nom.) (adjustable)

< 10 %

(peak-to-peak)

Lasers Overview


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9

Drive IR Laser Specifications (cont.)Parameter Nominal Spec Tolerance

Temporal: rep rate 120 Hz

power profile uniform (adjustable)

< 3 %

(RMS noise on the plateau)

profile FWHM 10 psec

(adjustable to

20 psec)

< 2 % RMS


profile rise/fall times 2 psec

Timing jitter

(with respect to the external RF source)

< 0.5 psec

(shot-to-shot)

Lasers Overview


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10

Drive LaserTiS

Oscillator (119MHz)

StretcherPulse

Shaper

Amplifiers

(preamplifier + final amplifier)

CompressorUV

Converter

To the Laser Heater

To EO Diagnostics

Lasers Overview04/29/2004 Sasha Gilevich

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To the Cathode

UV specs

IR specs

Tra

nspo

rt t

o th

e T

unne

l

UV Launch and Conditioning

(at the Gun)

Pumps

TiS Oscillator

(119MHz)

TiS Oscillator

(119MHz)Stretcher

TiS Oscillator

(119MHz)Stretcher

TiS Oscillator

(119MHz)Stretcher

TiS Oscillator

(119MHz)

Pulse Shaper

Stretcher

TiS Oscillator

(119MHz)

Pulse Shaper

Stretcher

TiS Oscillator

(119MHz)

Pulse Shaper

Stretcher

TiS Oscillator

(119MHz)

Pulse Shaper

Stretcher

TiS Oscillator

(119MHz)

Pulse Shaper

Stretcher

TiS Oscillator

(119MHz)

Pulse Shaper

Stretcher

TiS Oscillator

(119MHz)

Pumps

11

Drive Laser Development by Outside Vendors

Lasers Overview


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Demonstrated capability to build the IR system according to the specs

Can ship the system in 12 months

Can provide full integration

Will have service agreement

Showed similar estimated costs

Need some development to be done

Have expertise in UV conversion

All three companies

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Drive Laser Development by Outside Vendors

Procurement Plan:

Prepare Bid Package – June 2004Receive Vendors Proposals – August 2004Have Technical Review of Proposals – September 2004Evaluate the proposals – September 2004Issue the Award – October 2004

Lasers Overview


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13

Drive Laser Design IssuesUnresolved Issues:

Choice of the Temporal Pulse Shaping Technology Amplification of the Temporally shaped pulses Efficient UV Conversion of broadband temporally shaped pulses 25 mJ in the IR at 120 Hz is difficult

R&D: Temporal shaping R&D conducted with BNL UV conversion R&D with ANL Experiments at SLAC with spectral filtering Modeling of the UV conversion using SNLO software Temporal Shaping development by the outside vendor UV Conversion development by outside vendor

Lasers Overview


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14

R&D Effort

UV Conversion (ANL/SLAC)

Baseline UV Conversion tests

Spatial Profile Shaping

UV Launching

Sasha Gilevich

Lasers Overview [email protected]


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15

R&D Effort

Pulse Shaping (BNL/INFN/SLAC)

Baseline Pulse Shaping Tests

UV Conversion Tests with Pulse Shaping

Evaluate Effects of Shaping on the E-beam

Pulse Shaping (SLAC)

Temporal Shaping of IR pulses with spectral filtering and compressor tuning

Sasha Gilevich

Lasers Overview [email protected]


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16

UV Conversion

UV Conversion SetupUV Conversion Setup

SHG Nonlinear crystal

THG Nonlinear crystal

λ=255nm

Dichroic Separation Unit

To EO Diagnostic

To the Laser Heater


THG Nonlinear crystal


λ=765nm




λ=765nm


λ=382.5nm




To EO Diagnostic

To the Laser Heater

To the Photocathode

To EO Diagnostic

Lasers Overview





04/29/2004

17

UV Conversion Modeling

Optimizing the crystalsType of crystal

Crystal Length

Optimizing the input beamBeam Diameter

Beam Shape

Input (IR and blue) beams energy ratio (for THG)

Considering different setup methodology

Sasha Gilevich


04/29/2004

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Nonlinear CrystalsNonlinear Crystals

Crystal Walk off

765/382.5

mrad

GVD

765/382.5

10^5cm /sec cm-1

Deff

pm/V Angle

Tolerance

mrad cm

Tempe-rature Range Ko cm

Accept. Bandwidth

cm-1 cm

BBO I

o+o=e 0 / 70.32 -0.48 /

-1.16 1.99 0.33 17.31 15.34

CLBO I

o+o=e 0 / 36.50 -0.33 /

-0.860.503 0.70 23.71 27.18

LBO xy

o+o=e 0 / 17.52 -0.32 /

-0.82 0.722 1.35 14.69 24.02

SHG

Sasha Gilevich


04/29/2004

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Nonlinear CrystalsNonlinear Crystals

Crystal Walk off

765/382.5/ 255

mrad

GVD

765/382.5/ 255

10^5cm /sec cm-1

Deff

pm/V Angle

Tolerance

mrad cm

Tempe-rature Range Ko cm

Accept. Bandwidth

cm-1 cm

BBO I

o+o=e 0 / 0 / 87.38

-0.48 / -1.23 / -2.21

1.82 0.17 5.84 3.98 / 7.09

CLBO I

o+o=e 0 / 0 /

33.98 -0.33 / -0.89 / -1.61

0.799 0.50 6.39 7.05 / 12.53

KDP

o+o=e 0 / 0 /16.43 -0.24 /

-0.83 / -1.45

0.469 1.02 2.36 7.89 / 14.5

THG

Sasha Gilevich


04/29/2004

20


SHG in LBO and BBO I D=5mm E=20mJ

123456789

101112131415161718

0 0.5 1 1.5 2 2.5 3 3.5 4

Crystal Length, mm

Acc

p. B

an

dw

idth

,nm

O

utp

ut 4

00

nm

En

erg

y, m

J

Accpt Bw LBO E400 LBO

Accp Bw BBO E400 BBO

Sasha Gilevich


04/29/2004

Choice of the Crystal SHG

Lasers Overview

04/29/2004

BBO narrowband output

LBO narrowband output

LBO accept bandwidth

BBO accept bandwidth

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Sasha Gilevich


04/29/2004

Choice of the Crystal THG

Lasers Overview

04/29/2004

THG BBO I D=5mm E400/E800=13/6.46mJ and 11.68/7.78mJBBO I (solid) and KDP I (broken)

0123456789

101112

0 0.5 1 1.5 2 2.5 3 3.5 4

Crystal Length, mm

Pu

lse E

nerg

y,

mJ,

Accp

t B

an

dw

idth

, n

m

E267 BBO Accp Bw IR BBOAccp Bw blue BBO E267 KDPAccp Bw IR KDP Accp Bw blue KDP

KDP narrowband output

BBO narrowband output

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THG BBO I D=5mm E400/E800= 11.68/7.78mJSpatial Shaped ( Broken line) and Gaussian (Solid Line)

0

2

4

6

8

10

12

14

0 0.5 1 1.5 2 2.5 3 3.5

Crystal Length, mm

Puls

e E

nerg

y, m

J

E267 n=5

E267 n=1

Spatial Shaping

Sasha Gilevich


04/29/2004

Shaped

Gaussian

Input 20mJ T=10ps Narrowband

Gaussian

Shaped

Input pulse

050

100

150200250300

350400450500

550600650

-6.00E-03 -4.00E-03 -2.00E-03 0.00E+00 2.00E-03 4.00E-03 6.00E-03

x, m

Flue

nce,

J/m

^2

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UV Conversion ModelingSpatial Shaping

THG in BBO I E800/E400=7.78mJ/11.68mJ D=5mmD=5mm n=5

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

-5.0E-03 -4.0E-03 -3.0E-03 -2.0E-03 -1.0E-03 0.0E+00 1.0E-03 2.0E-03 3.0E-03 4.0E-03 5.0E-03

X, m

Norm

. FLu

ence

L=1mm

L=1.25mm

L=1.5mm

THG in BBO I D=5mm, E800/E400= 7.78/11.68mJ n=5

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

1.10

-12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12

T, ps

Norm

Pow

er

L=1mm

L=1.25mm

L=1.5mm

Sasha Gilevich


04/29/2004

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UV Conversion Modeling Temporal and Spatial ShapingSHG BBO I L=1mm Input E=20mJ Pulse Duration = 10 ps

Sasha Gilevich


04/29/2004

Output 400nm Beam

Output 800nm Beam

800nm

400nm

04/29/2004

Lasers OverviewLasers Overview

25

Status

The Laser Specifications are definedPotential vendors were selectedRequirements for the Laser Bay are specifiedR&D effort is outlinedBaseline WBS has been completedPreliminary layout of the Gun Region is underway

[email protected]

Sasha Gilevich04/29/2004

Lasers Overview

26

Drive Laser Overview

Milestones

Issue Request for proposals – June 2004

Review of Proposals – September 2004

Issue Award - October 2004

Completion of R&D – December 2004 (preliminary data – September 2004)

Receive the IR Drive Laser – October 2005

Start Installation – October 2005

Sasha Gilevich


04/29/2004

27

Temporal Pulse Shaping with the Dazzler

Sasha Gilevich


04/29/2004

Preliminary Results Using an Acousto-optic Dispersive Filter For Laser Pulse Shaping

A Ghigo, F. Tazzioli, C.Vicario, S. De Silvestri, M. Nisoli, S. Stagira, I Boscolo, S. Cialdi, L. Serafini

INFN

28

UV to the Cathode

injector lasers overview sasha gilevich, slac april 29, 2004

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