covesion

Laser Wavelength Conversion Experts

Who are we?

• Pioneers in PPLN (Periodically Poled Lithium Niobate) technology

• 2003 spin-out from Optoelectronics Research Centre at University of Southampton, UK

• Production of custom and standard crystals from crystal wafers

• Facilities & expertise includes:

– PPLN design expertise and software

– Core PPLN “poling” process by selective electrostatic domain inversion

– Laser testing

– Clean-room production and testing areas

– Lithography

– Wafer dicing and polishing

– In house 1064nm performance and lifetime testing

Benefits of PPLN Technology

• High efficiency

• Wide range of applications

• Easy control

• Excellent material stability

Technology

• Quasi Phase-Matching (QPM) achieved by are

periodically inverting Lithium Niobate crystal domains at

every coherence length.

• MgO doping raises damage limits to improve power

handling

Quasi-phasematched

Non phasematched

• PPLN offers highest non-linear properties for

commercial grade ferroelectric material

• Deff > 15pm/V (independent of process)

– Very high conversion efficiency

• Alignment insensitive

• No spatial beam walk-off; enables very long

crystal lengths

High Efficiency

Material Deff (pm/V)

MgO:PPLN >15pm/V

KTP 3.4pm/V

BBO 2.5pm/V

LBO 0.85pm/V

• All wavelength generating Mechanisms: SHG, SFG,

DFG, OPO

– Poled Periods from 4.5um (SHG Blue) a 30um+ (Mid-IR)

– 0.5 / 1mm thick, multiple periods per standard chip

– High damage thresholds

Wide Range of Applications

• Covesion created industry standard crystal format;

fabricated with a range of poling period paths.

• Frequency can be precisely tuned using

temperature control within a single path

• Fixed and tuneable conversion methods

Easy control

• MgO doped Lithium Niobate:

– Non hydroscopic

– High resistance to photorefractive damage effects

Excellent material stability

Why Covesion?

• High quality

• Uniquely uniform performance

• Fast response; large ex-stock range &

semi-custom options

• Unparalleled support from technology

pioneers

• Complete PPLN temperature controlled

solutions for fast development cycles

High quality

• Process developed and refined over 10+yrs period

• High yield allows consistent piece-to-piece performance

as confirmed hundred of customer-tested devices

• Use leading specialist external Anti-Reflective (AR)

coater for highest possible performance

• Consistent efficiency along y-axis:

• Patented fabrication process

– Consistent Domain Structure along thickness (z-axis)

• Provides Market Enabling Prices:

– Single process lithography step

gives low cost and high yields

z

Proven reliability & comprehensive testing facilities

Optical setup:

1. Beam stirring mirrors

2. Focussing lens

3. AR coated PPMgO:LN crystal, 15x 1 x 1mm3

; 30degC operating temperature

4. HR\AR @ 1064\532nm Beamsplitter (45°)

5. Thermal power meters

6. Scatter detector, monitoring possible AR damage

Complete temperature controlled

development environment

Crystal mounts

Ovens

Temperature controllers;

ultra stable to +/-0.01oC

Fast response from large ex-stock range & semi-

custom options

• Wide range of standard product available

from stock: 1 week worldwide delivery

• Large library of masks from 10yrs

operation allows off-the-shelf delivery or

semi-custom design in 6 weeks.

• Full custom designs normally delivered in

8 weeks.

Unparalleled support

• Depth of expertise from 10yrs operation and on-going

research

– Collaboration with OCR @ University of Southampton “a world

leading research organisation with roots going back to the

invention of the optical fibre in the 1960's.”

– OCR Professor Peter Smith is a founding director of Covesion

– 80% of staff hold Doctorates in lasers/non-linear optics

• Dedicated, highly qualified experts give detailed pre-

and post- sales technical applications support

• Custom device design, fabrication and testing

• Technology transfer and licencing opportunities

available

PPLN Product Range

M SHG 1550 - 0.5 - 30

M= MgO dopingFor high damage limit &

power handling

Conversion MethodSHG= Second Harmonic Generation

(frequency doubling)

SFG = Sum Frequency Generation

DFG = Difference Frequency Generation

OPO = Optical Parametric Oscillator

Nominal Laser Input

Wavelength

Range: 480 – 4500nm

Crystal ThicknessDetermines power

handling.

Values: 0.5, 1 mm

Crystal LengthDetermined by pump laser pulse mode:

Continuous Wave(CW), nanosecond (ns),

picosecond (ps), femtosecond (fs)

Range: 0.3mm (fs) – 40mm (cw)

Product options using example part number:

_ 3

Grating WidthDetermines power handling.

Standard values: 0.5, 1 mm

Custom values: 0.5-10mm

SHG: fixed IR -> Vis-IR conversion

SHG2100

Single fixed freq. -> single fixed freq.Examples

• 1550nm fs-Doubling– Recommend 1mm crystal length / 200fs pulse length

– Stock: 0.3 / 0.5 / 1mm length (typ. for 50-200fs pulses)

– Typ. Efficiency: 40% (up to 50% reported) ; 2-5nJ

pulses

– Damage Thresholds: 4GW/cm2

• 1064nm ns-Doubling– Typical length & stock items: 10 / 20mm

– Typ. Efficiency: 50%+; 50uJ, 2kW pulses

– Damage Thresholds: 1J/cm2

• 1064/1550nm cw Doubling– Typical length & stock items: 20 / 40mm

– Typ. Efficiency: 15-30% for 10W source (0.7% - 2% W-

1cm-1)

SHG1550

SHG1064

SHG1047SHG1030

SHG976

SHG1650

SHG1320

Wavelength

(nm)

SFG & DFG: tunable IR -> Green & IR convesion

Examples

• SFG Application (for example to 626nm)• Frequency mixing between 1050nm & 1550nm

• ~7W @ 626nm from 8.5W / 8.5W at 1050nm & 1550nm

• Reference: Hsiang-Yu Lo from the Group of Jonathan Hom, Trapped Ion Quantum Information Group / ETHZ

• DFG Application• Frequency mixing between 750-850nm & Nd:

YAG

• MDFG1: 2450–3000nm MDFG2: 2850–4700nm

• Achieved Efficiencies: 0.3-0.4mW W-2cm-1

• Typical outputs: i) 10uW / 2x100mW ii) 1mW / 2x1W

1 fixed &

1 tuneable input -> tuneable output

SFG1(1550 pump)

DFG1(1064 pump)

DFG2(1064 pump)

Tuneable

output

2853-4741

Tuneable

output

2450-3000

Tuneable

output

516-514

Wavelength

(nm)

OPO: Fixed IR -> tuneable IR

• Power scaling with elliptical beams

– Wider Aperture grating allows

scaling of pump powers

– Stock Part: 20 /40mm length,

periods 29~31um

– Phasematching: 1064nm 1650nm

+ 2996nm ; 31.27um / 67degC

• Application:

• ns-pulsed OPG / OPA

• ns-damage: 1J/cm2

• Redundancy

1 fixed input -> tuneable output

OPO1(1064 pump)

Tuneable

1410-4340

outputWavelength

(nm)

PPLN

Covesion:

technology partner from R&D to production

• High efficiency PPLN technology

• High quality

– 10yrs of process development

– World-class AR coating partner

• Uniquely uniform performance

– Patented fabrication method gives uniform efficiency throughout

thickness

• Fast response

– Ex stock delivery of large range from 1 week for standard products

– Full design service for custom applications within 8 weeks

• Unparalleled support from technology pioneers

– Expert pre- and post- sales support

• Complete PPLN temperature controlled solutions for fast

development cycles

– Enables simple, widely tuneable systems

Contact

Covesion Ltd

Email: sales@covesion.com

Web: www.covesion.com

Tel: +44 (0)1794 521638

Unit A7, The Premier Centre

Premier Way, Romsey

Hampshire SO51 9DG

United Kingdom