Using a freespace michelson wavemeter to measure the laser wavelength, we can tune the laser over a range greater. Tunable lasers thorlabs selection of tunable lasers includes benchtop external cavity diode lasers with wide tuning ranges, half butterfly gain chips, and spectroscopy kits. From optomechanical components to telecom test instrumentation, thorlabs extensive manufacturing capabilities allow us to ship high quality, well priced components and devices for nextday delivery. Pdf external cavity wavelength tunable semiconductor. Two kinds of ec configurations with the grating lines perpendicular a configuration and parallel b configuration to the pn junction are evaluated. Littman metcalf tunable external cavity diode laser, 630nm 2450nm, up to 100mw, patented technology, handsoff operation, large modehop free piezo tuning range, narrow linewidth, free space and fiber coupled versions.
Our lasers have been utilized in dualspecies mot experiments involving rubidium and. Tunable diode laser absorption spectroscopy tdlas is a technique for measuring the concentration of certain species such as methane, water vapor and many more, in a gaseous mixture using tunable diode lasers and laser absorption spectrometry. Dynamics of a green highpower tunable externalcavity. We have developed an enhanced littrow configuration extended cavity diode laser ecdl that can be tuned without changing the direction of the output beam. Pdf mode stability of external cavity diode lasers researchgate. The linewidth of external cavity diode lasers ecdls is an increasingly important characteristic for. Perot interferometer fpi device as the tuning element. Peter beyersdorf department of physics and astronomy dr. As a result, these lasers have quickly found use in the applications mentioned above. Laser cavity selfaligned external laser cavity modehopfree characteristic mode hops plague most tunable laser designs and are quite bothersome in many user applications. Semiconductor diode lasers are widely used in modern technology because of their compactness, low cost, and durability. Tunable singlefrequency diode lasers utilize a laser diode and a frequency selective element like a grating for laser frequency selection and tuning. The vortex plus tlb6800 is our highest performance precision finely tunable external cavity diode laser. They are available for individual wavelengths between 190 nm and 4000 nm, and deliver narrowlinewidth emission that is tunable in some systems up to 120 nm wide without a single modehop.
Selfaligned nondispersive external cavity tunable laser. It is based on an externalcavity configuration with simultaneous feedback and intracavity spatial separation of the lasers spectral components. Plus, having solid state lasers means that these are usually smaller than gas lasers giving the equivalent. Duarte, broadly tunable dispersive external cavity semiconductor lasers, in tunable laser applications, 2nd ed.
The firstorder diffracted beam provides optical feedback to the. The light emitted from the diode dl is collimated by an objective lens lc with short focal length 3 to 4. The system consists of an external cavity diode laser, a high power semiconductor amplifier ta, and two cascaded. Tunable externalcavity diode lasers in littrow and littmanmetcalf configuration. The passive alignment feature of the cavity is expected to reduce the assembly cost of tunable ecls.
External cavity laser diodes fibrecoupled laser diodes. External cavity laser diodes ecls are lasers with a very small line width, very good wavelength stability, and very low noise. There are many practical uses, from communications to spectroscopy. Tunable highpower blue external cavity semiconductor laser. In this paper, the temporal dynamics of a tunable highpower green external cavity diode laser system based on a gan bal and littrow external.
The velocity tlb6700 is our premier tunable diode laser system offering both wide and fine wavelength scanning. In the littmanmetcalf configuration 3, figure 2b, the grating orientation is fixed, and an additional mirror is used to reflect the firstorder beam back to the laser diode. Tunable highpower externalcavity gan diode laser systems. Change length andor phase section for fine tuning mems tunable vcsels. Littrow configurations there are advantages and disadvantages to both the. A tunable highpower narrowspectrum externalcavity diode laser system. Plus, having solid state lasers means that these are usually smaller than gas lasers giving the equivalent output. Modehopfree tuning over 140 ghz of external cavity diode. Tunable highpower blue external cavity semiconductor. Introduction since the irst demonstration of a room temperature continuous wave cw gan violet diode laser by nakamura et al. Littrow monolithic tunable external cavity laser, 370nm 1770nm, up to 300mw, patented technology, monolithic cavity design, handsoff operation, narrow linewidth, up to 30ghz modehop free tuning, free space and fiber coupled versions. The short external cavity laser uses an electrically controlled silicon micromachined fabry.
Move suspended top mirror by electrostatic or thermal tuning. Pdf external cavity wavelength tunable semiconductor lasers. Electronically tunable externalcavity laser diode article pdf available in optics letters 2422. Tunable external cavity diode lasers ecdls are employed in many applications, including coherent optical telecommunications, atomic and molecular laser spectroscopy, laser cooling, atomic clocks, environmental sensing, and optical microcavities. Ramendra bahuguna department of physics and astronomy dr. Tuning range and output power optimization of an external cavity diode laser at 455 nm mingjun chi, ole bjarlin jensen,and paul michael petersen dtu fotonik, department of photonics engineering, technical university of denmark, frederiksborgvej 399, p. Littmanmetcalf tunable diode lasers scientific lasers. Tunable highpower externalcavity gan diode laser systems in.
Widebandwidth modehopfree tuning of extendedcavity gan. Narrowbanded ecl lasers are characterized by a very small line width, low noise, and very good wavelength stability. Although externalcavity feedback with a grating is widely used to achieve tunable highpower narrowlinewidth broadarea diode laser bal system, the dynamics of such system is seldom studied. If the inline pdf is not rendering correctly, you can download the pdf file here. Tunable laser module for fibre optic communications. Controlling laser output via optical feedback a thesis submitted in partial fulfillment of the requirement for the degree of bachelor of science with honors in physics from the college of william and mary in virginia. External cavity wavelength tunable semiconductor lasers. While collimating the output of a diode laser is a relatively simple. Tuning range and output power optimization of an externalcavity. External cavity diode lasers ecdls are a standard way of building singlemode and narrowlinewidth sources 1, while keeping the intrinsic benefits of the semiconductor lasers such as. External grating reflector for modeselection filter.
Mode stability of external cavity diode lasers cdn. Wide and fine tunable external cavity diode laser new focus tunable external cavity diodes lasers lead the market with high performance, delivering true continuous modehopfree tuning over wide wavelength ranges. Several designs exist for external cavity tunable diode lasers used in atom trapping experiments. The laser module can be electrically modulated up to over 600 mhz. In addition to tunability, these applications often require narrow linewidth single mode operation. External cavity tunable lasers have been around for many years and now constitute a large group of semiconductor lasers featuring very unique properties. We present a new concept for an electronically tunable diode laser. Pdf electronically tunable externalcavity laser diode. Tunable external cavity diode lasers in littrow and littmanmetcalf configuration littmanmetcalf vs.
The tunable ecl concept is also experimentally tested with high power broad area laser diodes near 780 nm. Various laser types were investigated in sxc configurations using both planar and spherical external mirrors. The singlemode oscillation condition is controlled and stabilized by tuning the operating temperature. They are also called gratingstabilized diode lasers the common littrow configuration see figure 2a contains a collimating lens and a diffraction grating as the end mirror. In this chapter, both blue and green highpower tunable diode laser systems based on gan broadarea diode laser bal in litrow external cavity are demonstrated. Duarte, multipleprism grating designs tune diode lasers, laser focus world 29 2, 103109 1993 closedcavity multipleprism near grazingincidence grating configuration for tunable semiconductor lasers as described in the 1993 laser focus world article.
A sxc forces a multimode diode laser to lase on a single longitudinal mode. We present a new approach for extendedcavity diodelaser tuning to achieve wide modehopfree tuning ranges. Scholtena arc centre of excellence for coherent xray science, school of physics, the university of melbourne. Modehopfree tuning over 140 ghz of external cavity diode lasers without antireflection coating sourav dutta, 1, d. The cleaved end facet of the coupling fiber becomes an optical reflector and forms an external cavity with a laser facet. The electronical tunability is achieved by insertion of a liquidcrystal array as an electronically controlled aperture into the region of spatial separation of the spectral. Thorlabs specializes in the building blocks for laser and fiber optic systems. Tunable diode laser absorption spectroscopy wikipedia. Where to buy externalcavity diode lasers, ecdl, narrow. In this work we describe a simple external cavity laser diode equipped with a feedback control system, in which a highresolution positionsensitive detector detects the slight misalignment of the light within the cavity. Osa tunable singlemode fabryperot laser diode using a. Check our arcoated diode stock list for availability.
Monolithically integrated external cavity laser a schematic of the monolithicallyintegrated widely tunable laser with external cavity is shown in fig. Optomechanics, optics, optoelectronics, laser diodes, fiber optics and ase test sources as well as fiber optic. Widely tunable diode lasers with narrow spectral linewidth well below 1 mhz. This thesis describes the use of short external cavity sxc semiconductor diode lasers as single longitudinal mode sm tunable sources. In this work we describe a simple externalcavity laser diode equipped with a feedback control system, in which a highresolution positionsensitive detector detects the slight misalignment of. Pdf simple external cavity diode laser researchgate. Precision finely tunable external cavity diode laser. Characterization and development of an extended cavity. Precision finely tunable external cavity diode laser the new focus tunable external cavity diode lasers deliver true continuous modehopfree tuning. Some recent applications one of the benefits of the tunable diode laser is the wavelength diversi. Linewidths below 100 khz with external cavity diode lasers. A commercially available highpower ganbased blue laser diode has been operated in a simple littrowtype external cavity ec.
Tuning range and output power optimization of an external. The lens is chosen to compensate for abberations arising from the diodes packaging window. Scholtena school of physics, the university of melbourne, parkville victoria 3052, australia. The author explains how tunable external cavity diode lasers work, and why they are important. The test results show that the fpituned diode lasers can provide a costeffective solution for optical communication applications.
The lasers were designed at ucsb and fabricated using a heterogeneous photonic integration process design kit pdk and foundries developed under the darpa ephi program 27. Pdf mode stability is an important performance characteristic of external cavity diode lasers ecdls. Characterization and development of an extended cavity tunable laser diode by fnu traptilisa approved for the department of physics and astronomy san jose state university may 2014 dr. Littrow configuration tunable external cavity diode laser. Soa external to cavity provides power control currently used in many new dwdm systems variations highly reliable pdf 785 nm. Nov 27, 2001 we have developed an enhanced littrow configuration extended cavity diode laser ecdl that can be tuned without changing the direction of the output beam. The littmanmetcalf cavity configuration provides exceptional stability. Pdf a semiconductor diode laser having a modified littrow external resonator is described. Both manufacturers and distributors can be registered. For blue diode laser system, for highpower application, an output power around 530 mw over a 1. The output of a conventional littrow ecdl is reflected from a plane mirror fixed parallel to the tuning diffraction grating. Although external cavity feedback with a grating is widely used to achieve tunable highpower narrowlinewidth broadarea diode laser bal system, the dynamics of such system is seldom studied. Toptica tafhg pro highpower, tunable, frequencyquadrupled diode laser the tafhg pro is a tunable, diodebased laser source in the deep uv spectral range.
Introduction to multipleprism grating oscillator configurations for tunable semiconductor, andor diode, lasers. External cavity tunable lasers have been around for many years and now. They are used in optical communication and fibre sensor technology. Tunable externalcavity diode lasers tunable lasers usually use a diffraction grating as the wavelengthselective element in the external resonator. Sep 01, 2017 a commercially available highpower ganbased blue laser diode has been operated in a simple littrowtype external cavity ec. Narrow linewidth tunable external cavity diode laser using wide bandwidth filter daniel j. Monolithically integrated external cavity laser a schematic of the monolithicallyintegrated widelytunable laser with external cavity is shown in fig. Tuning range and output power optimization of an externalcavity diode laser at 455 nm mingjun chi, ole bjarlin jensen,and paul michael petersen dtu fotonik, department of photonics engineering, technical university of denmark, frederiksborgvej 399, p. Our aim was to combine the best aspects of previous designs but make improvements that would enable students to align and adjust the lasers more conveniently. Schawlowtowneshenry laser linewidth where hv is the photon energy, v g is the group velocity, n sp is the population inversion factor, and p out is the singlefacet output power. Review of scientific instruments 83, 023107 2012 narrow linewidth tunable external cavity diode laser using wide bandwidth. A tunable external cavity laser diode possessing a stable. The antireflection coating prevets the diode fron self lasing figure 2. Dynamics of a green highpower tunable externalcavity broad.
Their most conspicuous manifestation is in the powervswavelength characteristic at a constant diode current, which exhibits significant stairlike glitches. Littrow tunable diode lasers scientific lasers home. The aim was to make the paper as concise as possible without sacrificing, however, most important details. In this paper, the temporal dynamics of a tunable highpower green externalcavity diode laser system based on a gan bal and littrow external. Light emitted by a diode laser is not monodirectional and typically has a large bandwidth.
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