Solid-state dye lasers

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Solid-state dye lasers (SSDL) were introduced in 1967 by Soffer and McFarland. [1] In these solid-state lasers, the gain medium is a laser dye-doped organic matrix such as poly(methyl methacrylate) (PMMA), rather than a liquid solution of the dye. An example is rhodamine 6G-doped PMMA. These lasers are also referred to as solid-state organic lasers and solid-state dye-doped polymer lasers.

Dye laser

A dye laser is a laser which uses an organic dye as the lasing medium, usually as a liquid solution. Compared to gases and most solid state lasing media, a dye can usually be used for a much wider range of wavelengths, often spanning 50 to 100 nanometers or more. The wide bandwidth makes them particularly suitable for tunable lasers and pulsed lasers. The dye rhodamine 6G, for example, can be tuned from 635 nm (orangish-red) to 560 nm (greenish-yellow), and produce pulses as short as 16 femtoseconds. Moreover, the dye can be replaced by another type in order to generate an even broader range of wavelengths with the same laser, from the near-infrared to the near-ultraviolet, although this usually requires replacing other optical components in the laser as well, such as dielectric mirrors or pump lasers.

A solid-state laser is a laser that uses a gain medium that is a solid, rather than a liquid such as in dye lasers or a gas as in gas lasers. Semiconductor-based lasers are also in the solid state, but are generally considered as a separate class from solid-state lasers.

Laser dye

Laser dyes are large organic molecules with molecular weights of a few hundred mu. When one of these organic molecules is dissolved in a suitable liquid solvent it can be used as laser medium in a dye laser. Laser dye solutions absorb at shorter wavelengths and emit at longer wavelengths. Successful laser dyes include the coumarins and the rhodamines. Coumarin dyes emit in the green region of the spectrum while rhodamine dyes are used for emission in the yellow-red. The color emitted by the laser dyes depend upon the surrounding medium i.e.the medium in which they are dissolved. However, there are dozens of laser dyes that can be used to span continuously the emission spectrum from the near ultraviolet to the near infrared.

Contents

Organic solid-state narrow-linewidth tunable dye laser oscillator Duarte's multiple-prism grating laser oscillator.png
Organic solid-state narrow-linewidth tunable dye laser oscillator

Organic gain media

In the 1990s, new forms of improved PMMA, such as modified PMMA, with high optical quality characteristics were introduced. [3] Gain media research for SSDL has been rather active in the 21st century, and various new dye-doped solid-state organic matrices have been discovered. [4] Notable among these new gain media are organic-inorganic dye-doped polymer-nanoparticle composites. [5] [6] [7] An additional form of organic-inorganic dye-doped solid-state laser gain media are the ORMOSILs. [7] [8]

Ormosil is a shorthand phrase for organically modified silica or organically modified silicate. In general, ormosils are produced by adding silane to silica-derived gel during the sol-gel process. They are engineered materials that show great promise in a wide range of applications such as:

High performance solid-state dye laser oscillators

This improved gain medium was central to the demonstration of the first tunable narrow-linewidth solid-state dye laser oscillators, by Duarte, [8] which were later optimized to deliver pulse emission in the kW regime in nearly diffraction limited beams with single-longitudinal-mode laser linewidths of ≈ 350 MHz (or ≈ 0.0004 nm, at a laser wavelength of 590 nm). [9] These tunable laser oscillators use multiple-prism grating architectures [9] yielding very high intracavity dispersions that can be nicely quantified using the multiple-prism grating equations. [10]

F. J. Duarte Chilean-American physicist

Francisco Javier "Frank" Duarte is a laser physicist and author/editor of several well-known books on tunable lasers and quantum optics. He introduced the generalized multiple-prism dispersion theory, has discovered various multiple-prism grating oscillator laser configurations, and pioneered polymer-nanoparticle gain media. His contributions have found applications in a variety of fields including astronomical instrumentation, atomic vapor laser isotope separation, geodesics, gravitational lensing, laser medicine, laser microscopy, laser pulse compression, laser spectroscopy, nonlinear optics, and tunable diode lasers.

Laser linewidth is the spectral linewidth of a laser beam.

Multiple-prism grating laser oscillator

Multiple-prism grating laser oscillators, or MPG laser oscillators, use multiple-prism beam expansion to illuminate a diffraction grating mounted either in Littrow configuration or grazing-incidence configuration. Originally, these narrow-linewidth tunable dispersive oscillators were introduced as multiple-prism Littrow (MPL) grating oscillators, or hybrid multiple-prism near-grazing-incidence (HMPGI) grating cavities, in organic dye lasers. However, these designs were quickly adopted for other types of lasers such as gas lasers, diode lasers, and more recently fiber lasers.

Distributed feedback and waveguide solid-state dye lasers

Additional developments in solid-state dye lasers were demonstrated with the introduction of distributed feedback laser designs in 1999 [11] [12] and distributed feedback waveguides in 2002. [13]

A distributed feedback laser (DFB) is a type of laser diode, quantum cascade laser or optical fiber laser where the active region of the device contains a periodically structured element or diffraction grating. The structure builds a one-dimensional interference grating and the grating provides optical feedback for the laser. This longitudinal diffraction grating has periodic changes in refractive index that cause reflection back into the cavity. The periodic change can be either in the real part of the refractive index, or in the imaginary part. The strongest grating operates in the first order - where the periodicity is one-half wave, and the light is reflected backwards. DFB lasers tend to be much more stable than Fabry-Perot or DBR lasers and are used frequently when clean single mode operation is needed, especially in high speed fiber optic telecommunications. Semiconductor DFB lasers in the lowest loss window of optical fibers at about 1.55um wavelength, amplified by Erbium-doped fiber amplifiers (EDFAs), dominate the long distance communication market, while DFB lasers in the lowest dispersion window at 1.3um are used at shorter distances.

See also

Organic laser

Organic lasers use an organic material as the gain medium. The first organic laser was the liquid dye laser. These lasers use laser dye solutions as their gain media.

Organic photonics

Organic photonics includes the generation, emission, transmission, modulation, signal processing, switching, amplification, and detection/sensing of light, using organic optical materials.

Polymer substance composed of macromolecules with repeating structural units

A polymer is a large molecule, or macromolecule, composed of many repeated subunits. Due to their broad range of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass relative to small molecule compounds produces unique physical properties, including toughness, viscoelasticity, and a tendency to form glasses and semicrystalline structures rather than crystals. The terms polymer and resin are often synonymous with plastic.

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Tunable laser

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Digital holography

Digital holography refers to the acquisition and processing of holograms with a digital sensor array , typically a CCD camera or a similar device. Image rendering, or reconstruction of object data is performed numerically from digitized interferograms. Digital holography offers a means of measuring optical phase data and typically delivers three-dimensional surface or optical thickness images. Several recording and processing schemes have been developed to assess optical wave characteristics such as amplitude, phase, and polarization state, which make digital holography a very powerful method for metrology applications .

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The first description of multiple-prism arrays, and multiple-prism dispersion, was given by Newton in his book Opticks. Prism pair expanders were introduced by Brewster in 1813. A modern mathematical description of the single-prism dispersion was given by Born and Wolf in 1959. The generalized multiple-prism dispersion theory was introduced by Duarte and Piper in 1982.

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A liquid-crystal laser is a laser that uses a liquid crystal as the resonator cavity, allowing selection of emission wavelength and polarization from the active laser medium. The lasing medium is usually a dye doped into the liquid crystal. Liquid-crystal lasers are comparable in size to diode lasers, but provide the continuous wide spectrum tunability of dye lasers while maintaining a large coherence area. The tuning range is typically several tens of nanometers. Self-organization at micrometer scales reduces manufacturing complexity compared to using layered photonic metamaterials. Operation may be either in continuous wave mode or in pulsed mode.

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References

  1. ↑ Soffer, B. H.; McFarland, B. B. (1967). "Continuously Tunable, Narrow-Band Organic Dye Lasers". Applied Physics Letters. 10 (10): 266. Bibcode:1967ApPhL..10..266S. doi:10.1063/1.1754804.
  2. ↑ Duarte, F. J.; Taylor, T. S.; Costela, A.; Garcia-Moreno, I.; Sastre, R. (1998). "Long-pulse narrow-linewidth dispersive solid-state dye laser oscillator". Applied Optics. 37 (18): 3987–3989. Bibcode:1998ApOpt..37.3987D. doi:10.1364/AO.37.003987. PMID   18273368.
  3. ↑ Maslyukov, A.; Sokolov, S.; Kaivola, M.; Nyholm, K.; Popov, S. (1995). "Solid-state dye laser with modified poly(methyl methacrylate)-doped active elements". Applied Optics. 34 (9): 1516–1518. Bibcode:1995ApOpt..34.1516M. doi:10.1364/AO.34.001516. PMID   21037689.
  4. ↑ A. J. C. Kuehne and M. C. Gather, Organic Lasers: Recent Developments on Materials, Device Geometries, and Fabrication Techniques, Chem. Rev.116, 12823-12864 (2016).
  5. ↑ Duarte, F. J.; James, R. O. (2003). "Tunable solid-state lasers incorporating dye-doped polymer-nanoparticle gain media". Optics Letters. 28 (21): 2088–90. Bibcode:2003OptL...28.2088D. doi:10.1364/OL.28.002088. PMID   14587824.
  6. ↑ Costela, A.; Garcia-Moreno, I.; Sastre, R. (2009). "Solid state dye lasers". In Duarte, F. J. Tunable Laser Applications (2nd ed.). Boca Raton: CRC Press. pp.  97–120. ISBN   1-4200-6009-0.
  7. 1 2 Duarte, F. J.; James, R. O. (2009). "Tunable lasers based on dye-doped polymer gain media incorporating homogeneous distributions of functional nanoparticles". In Duarte, F. J. Tunable Laser Applications (2nd ed.). Boca Raton: CRC Press. pp.  121–142. ISBN   1-4200-6009-0.
  8. 1 2 Duarte, F. J., F. J. (1994). "Solid-state multiple-prism grating dye-laser oscillators". Applied Optics. 33 (18): 3857–3860. Bibcode:1994ApOpt..33.3857D. doi:10.1364/AO.33.003857. PMID   20935726.
  9. 1 2 Duarte, F. J. (1999). "Multiple-prism grating solid-state dye laser oscillator: optimized architecture". Applied Optics. 38 (30): 6347–6349. Bibcode:1999ApOpt..38.6347D. doi:10.1364/AO.38.006347. PMID   18324163.
  10. ↑ Duarte, F. J. (2015). "The physics of multiple-prism optics". Tunable Laser Optics (2nd ed.). New York: CRC Press. pp.  77–100. ISBN   978-1-4822-4529-5.
  11. ↑ Wadsworth, W. J.; McKinnie, I. T.; Woolhouse, A. D.; Haskell, T. G. (1999). "Efficient distributed feedback solid state dye laser with a dynamic grating". Applied Physics B. 69 (2): 163–169. Bibcode:1999ApPhB..69..163W. doi:10.1007/s003400050791.
  12. ↑ Zhu, X-L; Lam, S-K; Lo, D. (2000). "Distributed-feedback dye-doped solgel silica lasers". Applied Optics. 39 (18): 3104–3107. Bibcode:2000ApOpt..39.3104Z. doi:10.1364/AO.39.003104. PMID   18345240.
  13. ↑ Oki, Y.; Miyamoto, S.; Tanaka, M.; Zuo, D.; Maeda, M. (2002). "Long lifetime and high repetition rate operation from distributed feedback plastic waveguided dye lasers". Optics Communications. 214 (1–6): 277–283. Bibcode:2002OptCo.214..277O. doi:10.1016/S0030-4018(02)02125-9.
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