An external cavity diode laser is a diode laser based on a laser diode chip which typically has one end antireflection coated, and the laser resonator is completed with, e. All springs including flexures have been removed to create a robust, stable, and vibrationally inert device. For blue diode laser system, for highpower application, an output power around 530 mw over a 1. The littmanmetcalf cavity configuration provides exceptional stability. Widely tunable narrowlinewidth monolithically integrated external. Index terms semiconductor lasers, cavity resonators, laser tuning, photonic integrated circuits. Dfb lasers can be rapidly tuned over several wavenumbers by changing the injection current or laser temperature external cavity diode lasers can be tuned more than 100 cm1 12 4. Tunable singlefrequency operation of a diodepumped.
The micromachined tunable lasers have been developed using the micromachined mirrors to form the. We deploy a novel technique for the attainment of modehopfree continuous tuning over several tens. Design and characterization of an external cavity diode. We present a new concept for an electronically tunable diode laser. Line width 200 khz integrated over 50 ms or sharper 3. The configuration of our electronically tunable external cavity laser diode etecal is shown in fig. Tunable highpower externalcavity gan diode laser systems in. Tunable singlefrequency diode lasers consist of a laser diode and a frequency selective element like a grating, which controls the emission frequency. The littmanmetcalf cavity configuration provides exceptional stability, piezo modehopfree tuning range and narrow linewidth. Tunable highpower narrowspectrum externalcavity diode. In this paper, the temporal dynamics of a tunable highpower green external cavity diode laser system based on a gan bal and littrow external.
Tuning range and output power optimization of an external. Introduction high power laser diode bars have a broad multimode spectrum of several nanometers consisting of the superposition of the spectrum of each broad area emitter in the bar. File 1 noisespectrum analysed 24092016 scaling 8 1. 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. Pdf linewidths below 100 khz with external cavity diode.
Us6470036b1 tunable external cavity semiconductor laser. Continuouswave lasers exhibiting wide and continuous wavelength tunability are of considerable interest for a variety of applications including high resolution. Littrow tunable diode lasers scientific lasers home sacher. Cavity diode laser the new focus tunable external cavity diode lasers deliver true continuous modehopfree tuning.
The laser source development group at montana state university msu has extensive experience building highquality ecdls, which was leveraged to develop the. The short external cavity laser uses an electrically controlled silicon micromachined fabryperot interferometer fpi device as the tuning element. We exploit a number of strategies for enhancing the tuning range of external cavity quantumdot lasers. Characterization and development of an extended cavity. N2 we report a tunable selfinjection locked violet laser diode external cavity system exhibiting a continuous wavelength tunability of 5. Dfb laser arrays based on several thermal tuned dfb lasers. Sacher lasertechnik is technology leader for tunable high power external cavity diode lasers. Tunable highpower externalcavity gan diode laser systems.
It is our highest performance precision finely tunable external cavity diode laser. Coarse tuning is achieved by selecting the correct laser bar. Continuously tunable single frequency external cavity diode. Compact selfaligned external cavity lasers using volume gratings. In the last years, external cavity diode lasers ecdls have experienced a tremendous improvement. The external cavity is realized with class d antireflection coated diode lasers and with a high efficiency diffraction grating. The output power is coupled out via the rear facet of the laser chip for avoiding any beam walk. Littrow configurations there are advantages and disadvantages to both the.
Modehopfree tuning over 140 ghz of external cavity diode lasers. Characterization and development of an extended cavity tunable laser diode a thesis presented to the faculty of the department of physics and astronomy. We developed a series of tunable, narrowlinewidth, external cavity diode lasers. The littmanmetcalf cavity configuration provides exceptional stability, piezo mode. A tunable 980 nm external cavity laser based upon a singleangledfacet saf semiconductor laser diode is demonstrated that does not require antireflection coatings or additional external mirrors. Characteristics and applications of the short external cavity. Mar 27, 2021 pdf external cavity tunable lasers have been around for many years and now constitute a large group of semiconductor lasers featuring very unique. External cavity lasers using a mems structure for tuning the cavity length, such as devices commercialized by iolon. Dynamics of a green highpower tunable externalcavity broad. Design and performance of a frequency chirped external cavity diode laser, kevin s. External grating reflector for modeselection filter.
This results in the best performance for an external cavity diode laser system in littrow. Abstract we report on a diode pumped vertical external cavity surfaceemitting laser emitting around 852 nm for cesium atomic clocks experiments. Pdf mode stability of external cavity diode lasers researchgate. Physics, issue 86, external cavity diode laser, atomic. The purpose is to provide a thorough account of the stateoftheart of tunable external cavity diode lasers which is achieved by combining this account with basic concepts of semiconductor diode lasers and its tunability with monolithic structures. Broadly tunable highpower inasgaas quantumdot external. Tunable laser module for fibre optic communications.
A novel tuning mechanism is disclosed which provides for mechanical fm. We have designed and built a robust tunable external cavity diode laser that is easily constructed from commercial components. Improving the spectral performance of extended cavity diode lasers. Toptica offers diode laser systems with an external grating ecdl as well as systems with a frequencyselective element integrated within the semiconductor structure itself dfb diodes. Pdf littrow configuration tunable external cavity diode.
Aside from tunability, these applications often require narrow linewidth single mode operation. Grating rotation and vertical alignment are uncoupled, allowing simple tuning over the full. We have designed a 7quantumwell semiconductor structure optimized for low laser threshold. The conventional optomechanical external cavity tunable diode lasers have bulk sizes and slow speed, limiting their applications. Pdf external cavity wavelength tunable semiconductor. While all laser gain media allow small shifts in output wavelength, only a few types of lasers allow continuous tuning over a significant wavelength range there are many types and categories of tunable lasers. The vortex plus tlb6800 is our highest performance precision finely tunable external cavity diode laser. Pdf mode stability is an important performance characteristic of external cavity diode lasers ecdls. Distributed feedback dfb semiconductor lasers and vertical cavity surface emitting lasers. Laser cavity selfaligned external laser cavity modehopfree characteristic mode hops plague most tunable laser designs and are quite bothersome in many user applications.
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. Move suspended top mirror by electrostatic or thermal tuning. Their most conspicuous manifestation is in the powervswavelength characteristic at a constant diode current, which exhibits significant stairlike glitches. 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. A new design for a tunable external cavity diode laser. Turner for their assistance with the design and construction of associated electronics and vibration isolation. We report a tunable selfinjection locked violet laser diode external cavity system exhibiting a continuous wavelength tunability of 5. Characteristics and applications of the short external. Precision finely tunable external cavity diode laser the new focus tunable external cavity diode lasers deliver true continuous modehopfree tuning. Tunable lasers thorlabs selection of tunable lasers includes benchtop external cavity diode lasers with wide tuning ranges, half butterfly gain chips, and spectroscopy kits. The laser cavity housing is shock proof, thermally insulated with active temperature control, and incorporates.
The maximum output power of both laser systems is more than 1. Prior research on the combination of the grating and the fp etalon has been carried out for the tunable external cavity laser diode 14 15 1617. Pdf electronically tunable externalcavity laser diode. Absorption and raman spectroscopy, environmental analysis, process control, biomedical. Tunable external cavity diode laser using a micromachined. Tunable external cavity diode laser based on integrated waveguide structures.
The design and demonstration of a dial laser transmitter based on a tunable external cavity diode laser 3638 ecdl is presented in this paper as a possible alternate seed laser source. A tunable external cavity semiconductor laser incorporating a tunable bragg grating, including. However, since the first external cavity diode laser ecdl designs were. Construction and characterization of external cavity diode lasers. External or extended cavity diode lasers ecls based on littman 4 and littrow 5 configurations have wide tuning range and narrow linewidth. Vortex plus tunable external cavity diode lasers spectraphysics. The antireflection coating prevets the diode fron self lasing figure 2. First, the most common techniques for the diode laser wavelength tuning and applications for these devices are. Pdf external cavity wavelength tunable semiconductor lasers. A maximum output power of 480 mw and a sidemode suppression ratio greater than 45 db are achieved in the central part of the tuning range. The phase and amplitude balances inside the lasing cavity would be changed.
Tunable external cavity diode lasers in littrow and littmanmetcalf configuration littmanmetcalf vs. Oct 01, 2011 we report on the spectral properties of a diode laser with a tunable external cavity mirror, realized as an integrated optics waveguide circuit. The present invention provides a continuously tunable external cavity laser ecl with a compact form factor and precise tuning. The littrow external cavity feedback technique has been applied to achieve tunable narrowlinewidth diode laser from the violet to the infrared spectral range 9, 16,17. The avalanche discharge excimer laser is the most common format that is. Tunable violet laser diode system for optical wireless.
Tunable diode laser absorption spectroscopy wikipedia. An external cavity tunable diode laser employs an external reflector to reflect a portion of output light back into the lasing cavity. Zorabedian characteristics of grating external cavity semiconductor laser containing intracavity beam expanders, j. Change length andor phase section for fine tuning mems tunable vcsels. Development of a widely tunable amplified diode laser. Compact selfaligned external cavity lasers using volume. Design and characterization of an external cavity diode laser for nvcenter photoluminescence excitation john raihala1,2 1institute of nuclear theory reu, university of washington, seattle, wa 98195 2department of physics, university of chicago, chicago, il 60637 the nitrogen vacancy nv center is a point defect in diamond which shows potential to be used. The saf laser diode is comprised of a curved ridge waveguide that intersects the facet cleavage plane normally at one facet and at an angle at the other facet. Chuang et al tunable external cavity diode laser j. Turner for their assistance with the design and construction of.
High power laser diodes, external cavity, tunable, volume holographic gratings, selfaligned, passive alignment. In this chapter, both blue and green highpower tunable diode laser systems based on gan broadarea diode laser bal in littrow external cavity are. Singleangledfacet laser diode for tunable external. An external file that holds a picture, illustration, etc. Thermal and finite element analyses led us to the starflex design that provides stiff, reproducible rotational motion without any translation.
The linewidth of external cavity diode lasers ecdls is an increasingly important characteristic for experiments in coherent optical communications and atomic physics. Narrow linewidth tunable external cavity diode laser using. Continuously tunable single frequency external cavity. A record broadly tunable highpower external cavity inasgaas quantumdot diode laser with a tuning range of 202 nm 1122 nm24 nm is demonstrated. The new focus tunable external cavity diode lasers deliver true continuous modehopfree tuning. Tunable externalcavity diode lasers tunable lasers usually use a diffraction grating as the wavelengthselective element in the external resonator. Singleangledfacet laser diode for tunable external cavity. External cavity lasers using multipleprism grating arrangements for widerange tunability. Selfaligned nondispersive external cavity tunable laser. Us6282215b1 continuouslytunable external cavity laser. Tuning of the external cavity diode laser is achieved by rotating the diffraction grating. Precision finely tunable external cavity diode laser.
Littrow monolithic tunable external cavity laser, 370nm 1770nm, up to 300mw. Tuning over more than 5 nm around 488 nm was achieved with an external cavity diode laser in combination with a ppmgln crystal 4. The stationary and dynamical characteristics are investigated as well as the chaotic behavior of the modulated external cavity laser diode. It is based on an external cavity configuration with simultaneous feedback and intracavity spatial separation of the laser s spectral components. Tunable diode laser absorption spectroscopy tdlas, sometimes referred to as tdls, tls or tlas 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. This is the first book on tunable external cavity semiconductor diode lasers, providing an uptodate survey on the physics, technology, and performance of widely applicable coherent radiation sources of tunable external cavity diode lasers.
Tunable external cavity diode lasers ecdl are employed in many applications, including coherent optical telecommunications, atomic and molecular laser spectroscopy, laser cooling, atomic clocks, environmental sensing, and optical microcavities. The external cavity diode lasers under study exhibit no degradation of. Since its introduction, topticas dl pro leads the field of tunable diode lasers, thanks to its narrow linewidth, large modehopfree tuning range and highest vibration and. Osa electronically tunable externalcavity laser diode. Tunable diode laser absorption spectroscopy combustion.
Nearir lasers are compact, rugged, and fibercoupled dfb lasers can be rapidly tuned over several wavenumbers by changing the injection current or laser temperature external cavity diode lasers can be tuned more than 100 cm1 12 4. Linewidths below 100 khz with external cavity diode lasers. 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. 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. Even though the external cavity is short compared to that of other narrow bandwidth external cavity lasers, the spectral bandwidth of this tunable laser is as small as 25 khz fwhm. The firstorder diffracted beam provides optical feedback to the.
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. The linewidth of external cavity diode lasers ecdls is an increasingly important characteristic for. The effects of injection current and temperature indicate a robust system besides being costeffective and straightforward. A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. Wavelength range 890940 nm or better select wavelength to 0.
Tuning range and output power optimization of an externalcavity. Tunable external cavity diode laser littrow configuration. They have been used for optical clocks and highprecision spectroscopy, achieving 10 15. Mode stability of external cavity diode lasers wordpress at the. Owing to their availability over a broad spectral range, their tunability. We mainly focus on the laser diode coupled to a short external cavity by developing model equations appropriate to analyze this configuration. Performance of planarwaveguide external cavity laser for. Generation of singlefrequency tunable green light in a. The external cavity consists of an antiref lectioncoated ar commercial 670nm laser diode ld, a collimator, a diffraction grating 2000 grooves. Single knob tuning for both coarse and fine widely tunable dbr lasers.
The external cavity length and the diode mode have been chosen so that the overall gain peak occurs at. A new design for a tunable external cavity diode laser j. May 25, 2020 the moglabs ldl littrow external cavity diode laser is a research quality laser for advanced applications in atomic and quantum physics. Littrow configurations there are advantages and disadvantages to both the littmanmetcalf and littrow cavity designs. A novel interference filter which may be used to tune the ecl provides an absence of modehopping and reduced feedback from both spurious interference and reflections in the external cavity. The output power, spectral bandwidth and tunable range of the external cavity diode laser system are measured and compared with the two gratings at different. Tunable singlefrequency operation of a diodepumped vertical.
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