Apr 01, 2008 hochiao chuang, ricardo jimenezmartinez, simon braun, dana z. Osa highresolution spectroscopy and laser frequency. These characteristics are achieved by exploiting the. The laser system is based on a highpower gan diode laser in a littrow externalcavity. Single longitudinal mode blueviolet laser diode for data storage.
Also, the linewidth is reduced by a factor of more than from 40 mhz to less than 10 khz. External cavity diode lasers are used increasingly as sources of light in applications ranging from industrial photonic systems to basic laboratory research on the interaction of light and atoms. Ultrastable rubidiumstabilized externalcavity diode laser. They are used in optical communication and fiber sensor technology.
These are small enough to endanger a diode laser life. Mode stability of external cavity diode lasers wordpress at the. Mode stability of external cavity diode lasers cdn. Its frequency noise and intensity noise was comparable or better than the nonplanar ring oscillator npro and fiber laser between 0. Performance of planarwaveguide external cavity laser for. Compact selfaligned external cavity lasers using volume gratings. Eichler, narrowbandwidth highpower output of a laser diode array with a simple external cavity, opt. As diode lasers are very sensitive to optical feedback, two 30db isolators are necessary for high isolation. Both a holographic diffraction grating and a ruled diffraction grating are.
The output power is coupled out via the rear facet of the laser chip for avoiding any beam walk. Erratum mode stability of external cavity diode lasers sebastian d. This architecture is an extension of the cavity proposed by the authors for single frequency tunable. External cavity diode lasers ecdls have often been used for this purpose owing to their. Littrow configuration tunable external cavity diode laser with fixed direction output beam, rev. Both a holographic diffraction grating and a ruled diffraction grating are used as feedback elements in the. Design of external cavity semiconductor lasers to suppress wavelength shift and mode hopping l. External cavity diode laser with verylow frequency drift. A series of experiments are performed to characterize the light emitted from an external cavity diode laser. A 1542nm planarwaveguide external cavity laser pwecl is shown to have a sufficiently low level of noise to be suitable for precision measurement applications.
It uses a diffraction grating at grazing incidence for wavelength selection and output coupling. Compact selfaligned external cavity lasers using volume. The laser will oscillate at a wavelength resonant with the external laser cavity between the diode rear facet and the grating. Pdf simple external cavity diode laser researchgate. Design and development of an external cavity diode laser for laser. Ideally, the laser is also single mode, meaning we are outputting laser light in a very narrow range of frequencies and only those frequencies. We report a homebuilt external cavity diode laser ecdl, using a diode whose front facet is not anti reflection ar coated, that has a modehopfree mhf. The second approach is external cavity feedback technique used to improve the spectral quality of the highpower gan diode lasers and make the lasers tunable, 14. Results obtained in this study indicate that the external cavity diode laser is suitable for future applications in spectroscopy and.
The national time service center of china is developing a compact, highly stable, 698 nm externalcavity diode laser ecdl for dedicated use in a space strontium optical clock. The diode cavity is called the intrinsic or internal cavity. Modehopfree tuning over 140 ghz of external cavity diode lasers. Construction and characterization of a prototype external. Interference lter stabilized external cavity diode laser.
Pdf design and development of an external cavity diode. We present a stable design for an external cavity diode laser ecdl with an investigating the e ect of a rotating glass plate on the modehop free tunability. The external cavity diode laser is optimised and characterised near 780 nm. Pdf a semiconductor diode laser having a modified littrow external resonator is described. The laser system is based on a highpower gan diode laser in a littrow external cavity. Ultrastable rubidiumstabilized externalcavity diode. An externalcavity 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. The diode laser is positioned to illuminate a diffraction grating and a movable mirror is positioned to reflect a selected wavelength back into the cavity. An external cavity laser, or ecl, is a laser with a reflector that creates the cavity outside of the gain chip and allows the cavity to be longer than if it was confined to the gain chip. Light emitted by a diode laser is not monodirectional and typically has a large bandwidth. The mirror is mounted on a pivot so positioned to provide simultaneous rotation and linear. Us5319668a tuning system for external cavity diode laser. Painter california institute of technology abstract anenhancedtunablelittrowcon.
Narrow linewidth tunable external cavity diode laser using. Design and development of an external cavity diode laser. In order to develop its theory, an im proved form of differential equations which describe the behavior of the external cavity semiconductor laser ecsl is needed. Us6683895b2 wavelength agile external cavity diode laser. Osa externalcavity diode laser using a grazingincidence. Pdf improving an external cavity diode laser design semantic. The external cavity architecture, illustrated in fig. We have been able to measure the laser wavelength as it is tuned by more than 10nm using our wavemeter, without any other adjustments to beam direction. Thus, by using optical feedback from a diffraction grating, we are able to narrow the total bandwith. This was also extended to operate an external cavity diode laser ecdl with no observed mode hops. Single longitudinal mode blueviolet laser diode for data. Improved rate equations for external cavity semiconductor. Check our arcoated diode stock list for availability.
External cavity laser diodes fibercoupled laser diodes. The designed driver circuit was used to study the power and voltage variations versus current for a diode laser. Diodenlaser 405nm, sfaw210 mit externem resonator mit littrowaufbau. Pdf mode stability of external cavity diode lasers. Pdf characterization of external cavity diode laser. The light emitted from the diode dl is collimated by an objective lens lc with short focal length 3 to 4. External cavity diode lasers offer more stable output frequency and narrow spectral. Narrowbanded ecl lasers are characterized by a very small line width, low noise, and very good wavelength stability. Design and development of an external cavity diode laser for. T present, the external cavity semiconductor laser is a feasible means to realize a singlefrequency semi conductor laser. High power laser diodes, external cavity, tunable, volume holographic.
Manual tunable littmanmetcalf diode laser system sacher laser. Diode lasers unlike leds will not operate below a threshold current. Tunable external cavity diode laser littrow configuration. External cavity diode laser for ultracold atom experiments. Tunable external cavity diode laser using a micromachined. High power 7ghz bandwidth externalcavity diode laser array and its use in optically pumping singlet delta oxygen. The external cavity length and the diode mode have been chosen so that the overall gain peak occurs at. Realworld atomic sensors and other exacting applications require laser sources with specific size, environmental, and optical characteristics, placing unique constraints that most commercial laser systems do not meet.
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. Our aosense ecdl is built on a semimonolithic bench with a catseye design for stable operation in demanding environments. The laser is based on an external cavity diode laser ecdl system using a commercially available ganbase d highpower blue laser diode emitting at 448 nm. The lens is chosen to compensate for abberations arising from the diodes packaging window. 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. The practical and accessible information in this volume will enable the reader to study external cavity diode laser, to build up the systems of external cavity diode laser as well as to develop advanced systems for their particular applications. External cavity diode lasers are used increasingly as sources of light in. While collimating the output of a diode laser is a relatively simple problem to solve with lenses, narrowing the bandwidth of the output requires construction of an external cavity. 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. Mode stability of external cavity diode lasers sebastian d. As noted above, the split cavity laser is relatively susceptible to external vibration. Hildebrandt et al, antireflection coated blue gan laser diodes in an external cavity and doppler free indium absorption spectroscopy. Fang abstract in this report, a model of external cavity semiconductor laser is built, and then based on this model a program is coded for simulating the thermally induced wavelength shift and mode hopping. An external cavity has been developed for use with commercial diode lasers.
Next we use interferometry to make a precise measurement of the central wavelength. Due to the extreme sensitivity of laser frequency to cavity length 25mhznm for a 780nm diode, the grating mount, which is typically adjustable to allow for laser alignmentandtuning,shouldberigid. Pdf mode stability of external cavity diode lasers sebastian. The external cavity is realized with class d antireflection coated diode lasers and with a high efficiency diffraction grating. In this project we have created an external cavity diode laser ecdl, which selects a single wavelength from the entire output spectrum of the diode laser and drives the laser at this wavelength. External cavity laser diodes ecls are lasers with a very small line width, very good wavelength stability, and very low noise. This results in the best performance for an external cavity diode laser system in littrow. Main cavity constructed from a single aluminum block. This book will appeal to undergraduate and graduate students, scientists and engineers alike. The ultrashort external cavity fits inside a tocan 5. Kazumichi yoshii, haruki sakagami, hiroki yamamoto, sho okubo, hajime inaba, and fenglei hong, highresolution spectroscopy and laser frequency stabilization using a narrowlinewidth planarwaveguide external cavity diode laser at 1063 nm, opt. This configuration allows a gaalas diode laser to be tuned conveniently anywhere in a range greater than 20 nm.
Bright tunable external cavity diode laser using a micromachined silicon flexure and a volume holographic reflection grating for applications in atomic optics, journal of micronanolithography, mems, and moems 72, 021010 1 april 2008. Pdf singlefrequency external cavity green diode laser. External cavity diode laser setup with two interference filters. A method for tuning the wavelength of the laser is presented references. Scholten1, 1arc centre of excellence for coherent xray science, school of physics, the university of melbourne, victoria 3010, australia 2school of physics, monash university, victoria 3800, australia corresponding author. Manual tunable littrow laser system lynx s3 sacher laser. External cavity diode lasers offer more stable output frequency and narrow spectral bandwidth than the typical freerunning diode lasers. Aosense has developed a line of external cavity diode lasers ecdls designed to meet these needs, offering narrow linewidth in. External cavity diode laser setup with two interference.
By looking at the output power for di erent laser diode currents one obtains the characteristic curve shown in figure 3. Hochiao chuang, ricardo jimenezmartinez, simon braun, dana z. Wellknown achievements in atomic physics of the last two decades became possible due to the progress in the semiconductor diode lasers. Characteristics of the singlelongitudinalmode planarwaveguide external cavity diode laser at 1064 nm kenji numata,1,2, mazin alalusi,3 lew stolpner,3 georgios margaritis,3 jordan camp,2 and michael krainak2 1department of astronomy, university of maryland, college park, maryland 20742, usa 2nasa goddard space flight center, greenbelt, maryland 20771, usa. Apr 06, 2018 an external cavity laser, or ecl, is a laser with a reflector that creates the cavity outside of the gain chip and allows the cavity to be longer than if it was confined to the gain chip. The polarization maintained ber pmf can lter the laser beam to be pure fundamental transverse mode, and.
The national time service center of china is developing a compact, highly stable, 698 nm external cavity diode laser ecdl for dedicated use in a space strontium optical clock. Characteristics of the singlelongitudinalmode planar. The mirror is glued to a piezoelectric transducer pzt, which is glued to a mirror mount. A constant current source for an external cavity diode laser. A diode laser is simply a light emitting diode led with a feedback cavity. Tuning this cavity length across a wavelength allows the laser to be tuned across a free spectral range c2 l around the grating gain peak where c, is the speed of light and l, is the cavity length, typically 1. A tunable external cavity semiconductor laser is provided with a semiconductor laser diode, a diffraction grating and a movable mirror. Construction and characterization of external cavity diode. A littrow configuration external cavity diode laser. Aosense has developed a line of external cavity diode lasers ecdls designed to meet these needs, offering narrow linewidth in a compact package. Consequently, only when the threshold current is reached will the diode commence lasing.
608 1415 322 994 915 1056 602 1096 1191 709 1489 258 1353 798 505 522 394 422 594 943 1358 1277 557 1009 1347 1117 1181 1299 751 1410 473 1053 840 572 439 454 857 1041 306 434 787