As different applications require saturable absorbers with very different parameters, different devices are used. The broadband absorption range of the singlewall carbon nanotubes allows the stable modelocking behavior at 1. Next, optical deposition technique was demonstrated to fabricate the sa. Saturable absorption is a property of materials where the absorption of light decreases with increasing light intensity. Three possible situations can appear, depending on the values. We derive the semiclassical equations governing the response of a solidstate monochromatic laser with saturable absorber driven by an external coherent field. T1 saturable absorberbased singlelongitudinal mode tunable fiber laser using a faraday rotator mirror as the rear cavity end. Saturable absorbers are mostly used for passive q switching and mode locking of lasers. The behavior of the emitted field intensity versus either the driving field intensity or the pump parameter of the amplifying atoms displays the same qualitative behavior. Saturable and nonsaturable process of sugar uptake. Sapphire laser by graphene saturable absorber in hyung baek, hwang woon lee, sukang bae 1, byung hee hong, yeong hwan ahn, dongil yeom, and fabian rotermund department of physics and division of energy systems research, ajou university, suwon, gyeonggi 443749, korea.
Uptake of sugars into cells by a saturable process increased. We show that the energy absorbed by a saturable absorber is a. Twodimensional 2d nanomaterials, especially the transition metal sulfide semiconductors, have drawn great interests due to their potential applications in viable photonic and. The past decade has witnessed tremendous achievements of ultrafast fiber laser technologies due to rapid developments of saturable absorbers sas based on, in particular, nanomaterials such as 0d. A novel approach to integrated graphene saturable absorbers for ultrafast pulse generation in an all fibre ring laser cavity italian keywords. Sizedependent saturable absorption and modelocking of. Osa passive synchronization of allfiber lasers through. As an example for the latter, figure 1 shows how the reflectivity of a slow saturable absorber device a sesam, see below varies with the saturation parameter, which is related to the incident pulse energy. Keller, modelocking with slow and fast saturable absorbers whats the difference. On occasion, with very large doses, absorption can slow due to the large amount of drug present in a confined space. Yag and a passive negative feedback element gaas is reported. Elganainy1,2, 1department of physics, michigan technological university, houghton, michigan 49931, usa 2henes center for quantum phenomena, michigan technological university, houghton, michigan 49931, usa 3center for nanoscale science and technology, national institute of.
At sufficiently high incident light intensity, atoms in the ground state of a saturable absorber. Chapter 8 semiconductor saturable absorbers sofar we only considered arti. Modelocking with slow and fast saturable absorberswhats. Department of physics, indian institute of technology, kharagpur, india. Kopylova, aleksey ivanenko, boris nyushkov,3,4 sergey kobtsev,3 5alexey kokhanovskiy,3 alexander khegai,5 mikhail melkumov, maria burdanova,6 6michael staniforth, james lloydhughes,6 albert g.
In this paper, we have prepared three types of bp dispersions with different sizes utilizing the liquid phase exfoliation method. Theory of mode locking with a fast saturable absorber hermann a. Nonhermitian engineering of synthetic saturable absorbers. Until the end of the 1980s, ultrashort pulse generation was dominated by dye lasers, where modelocking was. In situ characterization of semiconductor saturable absorber mirrors in an operating yb. A decrease in the absorption coefficient of certain nonlinear materials at high intensities in the incident radiation. This force is excited by the kerker effects inside. A practical topological insulator saturable absorber for. Jun 15, 2017 saturable absorbers sa operating at terahertz thz frequencies can open new frontiers in the development of passively modelocked thz microsources. Here, nonequilibrium electrons translate a semiconductor tis2 material into a plasma to generate broad band nonlinear optical saturable absorption w. Supporting information ionic liquid gated carbon nanotube saturable absorber for switchable pulse generation yuriy gladush,1 1aram a. A simplified method of dispersed nanographenebased sas sidepolished fiber device with controllable polished length and depth was also developed. Lasers with saturable absorber driven by a coherent field.
Novel saturable absorber devices grown using rf and magnetron rf sputtering by rohit prativadi prasankumar b. Theory of mode locking with a fast saturable absorber. Keller ultrafast laser physics, institute of quantum electronics, swiss federal institute of technology. Elganainy1,2, 1department of physics, michigan technological university.
Saturable absorber incorporating graphene oxide polymer. Yag, while for mode locking it is common to use semiconductor absorbers sesams. Atomiclayer graphene as a saturable absorber for ultrafast pulsed lasers by qiaoliang bao, han zhang, yu wang, zhenhua ni, yongli yan, ze xiang shen, kian ping loh, and ding yuan tang. Nonequilibrium electrons induced by ultrafast laser excitation in a correlated electron material can disturb the fermi energy as well as optical nonlinearity. Keller ultrafast laser physics, institute of quantum. Saturable absorber article about saturable absorber by. Excitability and coherence resonance in lasers with saturable absorber. Osa fewlayer mos2 saturable absorbers for shortpulse. The laser was operated at a central wavelength of 1558. The generation of femtosecond pulse laser in the erbiumdoped fiber laser system is presented by integrating of the nanographenebased saturable absorbers sas. Particularly for passive mode locking but also for q switching, semiconductor saturable absorber mirrors also called sesams are frequently used 5. Mode locking with a slow solid state saturable absorber. The proposed saturable absorber will pave the way for graphenebased wideband photonics.
Laser modelocking with saturable absorbers article pdf available in ieee journal of quantum electronics 36. The dependence of geometry of a graphenedeposited sidepolished fiber device on. It is shown that the modulation depth of the sa significantly affects the pulse duration at the laser output. Thereafter, a grapheneclad microfiber saturable absorber was proposed by wrapping the graphene layer around the microfiber, which resulted to loosely attached graphene layers due to the absence of. Ionic liquid gated carbon nanotube saturable absorber for. Saturable absorption article about saturable absorption. Saturable reactor winding configurations osborne has been involved in a wide variety of saturable reactor design projects over the years. This saturable absorber is compatible with current fibre lasers and has many merits such as low saturation. Fewlayer molybdenum disulfide mos2 is emerging as a promising quasitwodimensional material for photonics and optoelectronics, further extending the library of suitable layered nanomaterials with exceptional optical properties for use in saturable absorber devices that enable shortpulse generation in laser systems. The role of the saturable absorber in a modelocked fiber. Nanographenebased saturable absorbers for ultrafast fiber. Pdf allfiber saturable absorbers for ultrafast fiber lasers.
Ws2 as a saturable absorber for ultrafast photonic. Ionic liquid gated carbon nanotube saturable absorber for switchable pulse generation. We present the synchronization of two allfiber modelocked lasers, operating at 1. Our gcmbased saturable absorber can generate ultrafast optical pulses within 1. The eu 2 o 3 was synthesized using casting technique and the resulting eu 2 o 3 thin film was introduced between two optical fiber ferrule connectors to form a sa. In situ characterization of semiconductor saturable. Quasiautocorrelation system based on carbonnanotube saturable absorber is demonstrated at 1550nm with 75fj pulses measured. Thereafter, a grapheneclad microfiber saturable absorber was proposed by wrapping the graphene layer around the microfiber, which resulted to loosely attached graphene layers due to the absence of magnesium fluoride mgf 2 substrate. Find, read and cite all the research you need on researchgate. We experimentally investigated the role of the saturable absorber sa in a modelocked fiber laser. If you encounter saturable drug absorption, there is generally no harm because higher doses will not result in higher drug exposure. In this work, tungsten disulfide ws2 based sa for ultrafast photonic applications was demonstrated.
Magnetic amplifier technology involves unique techniques that can be tailored to match the fit, form, and function of your application. Paper modelocked fiber laser with mose 2 saturable. Users are not otherwise permitted to reproduce, republish, redistribute, or sell. Grapheneclad microfibre saturable absorber for ultrafast. Semiconductor saturable absorber mirrors sesams for. Continuouswave operation of many longitudinal modes with randomly distributed phases in a fabryperot cavity containing a laser medium and a saturable absorber is investigated theoretically.
Until the end of the 1980s, ultrashort pulse generation was dominated by dye lasers, where modelocking was based on a balanced saturation of both gain and loss, opening a steady. Design and characterization of semiconductor doped silica. Design and characterization of semiconductordoped silica. Most materials show some saturable absorption, but often only at very high optical intensities close to the optical damage.
This work is a step in the development of graphene as a saturable absorber comparable to but substantially cheaper than semiconductor saturable absorber mirrors sesams, and towards the. See information transmission loss of fiber coupled sa pdf, available fibers. The atomic linewidths of both media are assumed to be homogeneously broadened. Both lasers operate in the solitonregime, achieving a synchronized repetition rate of. Continuouswave operation of many longitudinal modes with randomly distributed phases in a fabryperot cavity containing a laser medium and a saturable absorber is investigated.
Optimizing and applying graphene as a saturable absorber. Novel saturable absorber devices grown using rf and. Nov 21, 2014 twodimensional 2d nanomaterials, especially the transition metal sulfide semiconductors, have drawn great interests due to their potential applications in viable photonic and optoelectronic devices, such as saturable absorbers sas and optical switches, etc. These are also suitable for passive q switching, particularly at lower pulse energies. Rp photonics encyclopedia saturable absorbers, passive. Saturable absorber, coherent population oscillations, and. Generation of qswitched and modelocked pulses with eu2o3. Then the sa was positioned in the edfl ring cavity. In this paper, europium oxide eu 2 o 3 is used as a saturable absorber sa to produce qswitched and modelocked pulses in an erbiumdoped fiber laser edfl cavity. Pdf excitability and coherence resonance in lasers with. We investigate the differences in the dynamics of lasers modelocked by fast and slow saturable absorbers. In general, saturable absorption does not occur in situations with passive uptake.
Compared with traditional saturable absorbers, such as semiconductor saturable absorber mirrors sesams 10,11, singlewalled carbon nanotubes swcnts 12, graphene, transitional metal. Saturable absorberbased singlelongitudinal mode tunable. A decrease in the absorption coefficient of certain nonlinear materials at high intensities in the incident radiation explanation of saturable absorber. Yag has become the solidstate passive qswitch material of choice for 1 micron laser systems, offering several significant advantages over active acoustooptic and electrooptic devices, including. Slow saturable absorbers can already generate al modelocking with slow and fast saturable absorbers whats the difference. A quasiautocorrelation system based on carbon nanotube. Particularly for passive mode locking but also for q switching, semiconductor saturable. New jersey 07733 received 3 february 1975 this paper presents a closedform analysis of saturable absorber mode locking of a homogeneously broadened laser. Sapphire laser by graphene saturable absorber in hyung baek, hwang woon lee, sukang bae 1, byung hee hong, yeong hwan ahn, dongil yeom, and fabian. Additional coupling loss of about 15 % reduces the transmittance of the fiber coupled sa in comparison to a free space setup. New jersey 07733 received 3 february 1975 this paper presents a closedform analysis of. Department of physics, indian institute of technology. The system is described by a coupled set of rate equations including noise terms as well as the dependence of the population.
Compared with traditional saturable absorbers, such as semiconductor saturable absorber mirrors sesams 10,11, singlewalled carbon nanotubes swcnts 12, graphene, transitional metal dichalcogenides 14,15, black phosphorus 16,17, topological insulator saturable absorber possesses many good qualities, such as low saturable absorption threshold, large modulation depth 18, 19. See information transmission loss of fiber coupled sa pdf. Saturable absorbers sa operating at terahertz thz frequencies can open new frontiers in the development of passively modelocked thz microsources. Sauerbrey pulses as short as 100 fs were obtained with a 2% modulation depth saturable absorber. This work is a step in the development of graphene as a saturable absorber comparable to but substantially cheaper than semiconductor saturable absorber mirrors sesams, and towards the development of graphenebased optical and electrooptical devices for lasers.
This saturable absorber is compatible with current fibre lasers and has many merits such as low saturation intensities, ultrafast recovery times, and wide wavelength ranges. Most materials show some saturable absorption, but often only at very high optical. Stabilization of solitonlike pulses with a slow saturable. Modeling of wavelength conversion using switching bistability in a vertical cavity semiconductor saturable absorber. A prominent candidate for a saturable absorber is semiconductor material, which was pioneered by islam, knox and keller 123 the great advantage of using. Supporting information ionic liquid gated carbon nanotube. Fewlayer molybdenum disulfide mos2 is emerging as a promising quasitwodimensional material for photonics and optoelectronics, further extending the library of suitable layered nanomaterials with.
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