Selecting the proper optic for an ultrafast application is key to the success of your experiment. Standard, general purpose optics may not be the best choice for ultrafast. For example, the larger material thickness of lenses and dielectric coatings of mirrors will induce dispersion and interference effects that will be detrimental to the ultrashort pulses. Newport has analyzed these effects and has introduced a comprehensive set of optics specially designed for Ultrashort pulse applications.
Standard dielectric mirror coatings can cause significant dispersive effects for ultrashort pulses, such as those produced by Ti:Sapphire lasers. The dispersion of the material and the interference effects between coating layers result in phase variations at specific wavelengths. Since the group delay is related to the slope of the phase variation, these wavelength regions introduce significant GDD errors that can broaden and distort your pulse. Therefore, for applications that require steering ultrashort pulses, we suggest using our Ultrafast Mirror Selection Guide below.
For more information about selecting ultrafast optics, please see our Ultrafast Laser Optics white paper about balancing costs with successful outcomes.
| Series | Typical Performance | Diameter (mm) | Mirror Surface | GDD, Cubic Term | |
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FemtoOptics Femtosecond Optimized Silver Mirrors | R>99% @ 600-1000 nm R >97% @ 470-1000 nm |
25.4 & 50.8 | Flat | Inexpensive option for very low GDD(1) |
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FemtoOptics Femtosecond Optimized Concave Mirrors | R>99% @ 600-1000 nm R>97% @ 470-1000 nm |
25.4 (EFL 50-1500 mm) |
Concave | Near zero GDD over extended bandwidth |
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FemtoOptics Chirped Mirror Matched Pair | R>99.5% @ 700-890 nm | 25.4 | Flat | -45 fsec2 at 800 nm |
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FemtoOptics High Reflector Harmonic Mirrors | R>99% @ 400 or 267 nm | 25.4 | Flat | Near zero GDD within specified wavelength range |
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Low GDD Broadband Mirror for Ultrashort Pulses | R>99% @ 700-930 nm | 12.7, 25.4 & 50.8 | Flat | Near Zero GDD through wavelength range |
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Low GDD Concave Mirror for Ultrafast Pulses | R>99% @ 700-930 nm | 25.4 & 50.8 (EFL 50-1000mm) |
Concave | Near zero GDD through wavelength range |
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Chirped Mirrors for Ultrashort Pulses | RP>99.8% @ 700-900 nm | 25.0 | Flat | Negative GDD up to -140 fsec2 With near zero cubic term |
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Standard Broadband Turning Mirrors for Ultrashort Pulses | R>99.6% @ 680–1060 nm | 25.4 & 50.8 | Flat | High Reflectance with neutral GDD and cubic term |
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High Performance Ultrafast Broadband Turning Mirrors | R>99.6% @ 670-1340 nm | 25.4 | Flat | Optimized for neutral GDD across bandwidth of Insight® Laser |
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Ytterbium Doped Laser Mirrors | R>99.5% @ 520 & 1040 nm | 25.4 | Flat | Designed for low GDD for Spirit® One™ Laser |
(1) Mirror also useable for wavelengths outside standard Ti:Sapphire range. Please contact us for any customized shapes or special requirements.
Beam sampling, beam splitting, focusing or polarization changes can be done with our specially designed optics for Ultrashort pulses listed below. Special considerations have been made to ensure that pulse dispersion will be minimized.
| Series | Performance | Diameter/Size (mm) | Shape | Key Feature | |
|---|---|---|---|---|---|
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FemtoOptics Ultrathin Windows | AR coating R<0.4% @ 620-980 nm | 12.7, 25.4 & 30 | Round Flat | Ultrathin thickness allows for fine tuning of positive GDD |
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FemtoOptics P-Polarized Beamsplitters | R=67%, 76%, 80% or 90% @ 800 nm | 25.4 | Round Flat | Minimum GDD for beam splitting of intense pulses down to 25 fs or less |
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FemtoOptics Wedges | Optional AR coating R<0.5% @ 650-1040 nm | 20 x 30 & 20 x 50 | Rectangular Wedge | Dispersion fine tuning over a wide dynamic range |
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UF Optimized AR Coated Fused Silica Plano-Convex Lenses | R<1% @ 660-1380 nm R≤2.5% @ 640-1500 nm |
12.7 & 25.4 | Round | Custom coating provides optimal antireflection across broad wavelength range with minimal dispersion |
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Beam Sampler for Ultrashort Pulses | Ravg<0.75% @ 45° AOI, 660-1000 nm | 25.4 | Round Flat | Ultra-thin substrate produces minimal dispersion |
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Beamsplitters for Ultrashort Pulses | Rs=50 ±5 % @ 700-950 or 680-1080 nm | 25.4, 50.8 | Round Flat | Large bandwidth with low dispersion |
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Pellicle Beamsplitters | Ultra-thin, light weight beamsplitter @ 375-2400 nm | 51.6 mm clear aperture | Round Flat | Near zero dispersion |
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Ultrafast Laser Harmonic Beamsplitters | RS>99.8% @ 400 nm Ts>95% @ 800 nm |
25.4 | Round Flat | 3 mm thick substrate, low dispersion |
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Brewster Angle Dispersing Prisms for Ultrashort Pulses | Optimized for 185-2100 or 370-2000 nm | 15.0 & 25.0 | Triangular Prism | UV Fused Silica, LaKL21 or SF10 materials to optimize dispersion compensation |
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Achromatic Zero-Order Quartz-MgF2 Waveplates | Retardation Accuracy from ±λ/50 to ±λ/100 | 25.4 | Flat, air-spaced | Quartz and MgF2 offer wide wavelength range |
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Glan-Laser Calcite Polarizers | Extinction ratio>100,000:1 | 25.0 with 1.063-20 thd | Air spaced optics | Air-spaced for high laser damage resistance |
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Thin Film Polarizers For Ultrashort Pulses | TP, avg >96%, RS, avg >80% @ 700-950 nm TP, avg > 95%, RS, avg > 99% @ 785-815 nm |
14.3 x 28.6 | Flat, Rectangular | AOI of 70° ±2° |
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Broadband Hollow Retroreflectors | 1, 2, or 5 arc sec parallelism | 25.4 & 63.5 aperture | Round | Total wavefront distortion ≤ λ/3 |
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Broadband Ultrafast Variable Beam Attenuators | Extinction Ratio Tp/Ts > 500:1, 1000:1 average | 10 mm clear aperture | Cubic | Minimal stretching for ultrafast pulses > 70 fs |
| Opto-Mechanical Mount Series | Breadboard Series | ||
|---|---|---|---|
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Optical Delay Line Mirror Mount |  |
Solid Aluminum Breadboards |
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SUPREMA Series Precision Stainless Steel Mirror Mounts |  |
PG Series Optical Breadboards, Precision Grade |
Pre-selected optics and opto-mechanical components are offered at a discount in our Optical Delay Line Components Kits for building delay lines of single, dual or quadruple pass. (Note that Motorized Linear Translation Stages and Motion Controllers are sold separately.)
Newport's Ultrafast Oscillator (
Mirrors can be categorized into four groups: standard dielectric, standard metallic, ultrafast dielectric, and ultrafast metallic.
Standard dielectric mirrors are not recommended for ultrafast applications due to significant dispersion effects, so we do not quantify their GDD as a standard specification.
Standard metallic mirrors normally feature low GDD – thus, they are acceptable for applications using multiple laser sources or an OPA, where it is often needed to cover a wavelength range broader than what a single ultrafast dielectric mirror is designed for. However, standard metallic mirrors suffer from more losses (lower reflectivity) compared to ultrafast dielectric mirrors and are therefore not recommended for setups where ultrafast pulses experience multiple reflections.
For applications that require high reflectivity and guaranteed GDD, ultrafast dielectric mirrors are the best choice. Ultrafast metallic mirrors (coating code EAG.1 or EAG.2), with a metallic coating and ultrafast dielectric overcoat to minimize losses, are a compromise and suitable for a wide range of ultrafast applications.
Using a Spectra-Physics Mai Tai SP ultrafast laser with a center wavelength of 800 nm, Newport has measured auto-correlations of pulses bouncing twice from each kind of mirror to show how they influence and distort the pulse duration:
| Mirror | Coating Type | Conclusions |
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| Standard Dielectric |
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| Standard Dielectric |
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| Standard Dielectric |
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| Standard Metallic |
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| Ultrafast Dielectric |
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| Ultrafast Dielectric |
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