Experimental layout of the frequencyshifted feedback. Pulsed frequency shifted feedback laser for accurate long distance measurements. The approach adopted for this study included three parts. Laser dynamics under frequencyshifted optical feedback with. Jackson1 1mq photonics, school of engineering, faculty of science and engineering, macquarie university, north ryde, nsw 2109, australia corresponding author. The operation of an intracavity frequency shifted feedback fsf laser exhibits a remarkable range of properties, some of which have been described previously. A distributed feedback dfb laser is used in a frequency shifted external cavity configuration to generate a frequency comb. Frequency stabilised grating feedback laser diode for atom. Jones optical sciences opti 511l fall 2017 semiconductor lasers 2 weeks. The dynamics are mapped as a function of the level of frequency shifted feedback fsf and the injection. In the first, a comprehensive study of the effect of phase noise from lasers and other sources on photonic phased array systems was considered. Dynamics of a semiconductor laser with frequency shifted feedback. This study considered the influence of additive, as well as multiplicative noise in. Optical frequencydomain ranging using a frequencyshifted.
This page will automatically redirect to the new ads interface at that point. The frequency shift of the optical feedback is the. In contrast to previous theoretical predictions, it is found that the achievable bandwidth and a figure of merit, defined for maximizing the product of the bandwidth and output power for the fsf laser, are mainly determined by the spectral width of the gain. Here we report a more complete analysis of the dependence of the output power upon pump laser power, based on simulations with an extended rate equation model and the use of phase space analysis. The transmissive one is frequency shifted by a pair of acoustooptic modulators aom 1 and aom 2, the central frequencies are. If the fsf laser is seeded by a continuouswave laser a frequency comb spanning the output spectrum appears in addition to the broadband emission. Strong response to external frequencyshifted feedback. Improved design of a frequencyshifted feedback diode. Photonic microwave oscillator based on monolithic dfb. Dynamics of the output of a semiconductor laser with frequency shifted optical feedback system is systematically analyzed.
We illustrate the new analysis by showing how short frequency chirped. The influence of external frequency shifted feedback on a dfb. The laser produced 4mw average output power with an instantaneous linewidth of semiconductor laser with frequency shifted feedback yoann noblet, joshua p. Photonic microwave oscillator based on monolithic dfb lasers with frequency shifted feedback l. Osa frequency stabilization of semiconductor lasers by. Reconfigurable optical signal processing based on a. In this case, the decrease in r can be compensated by. Negative electronic feedback nef is a promising technique to improve the coherence properties of semiconductor laser diodes lds. Describe how a semiconductor laser diode works what determines the frequency that is emitted. We report results on ranging based on frequencyshifted feedback fsf lasers with two different implementations.
An analytical expression is obtained for the comb frequency bandwidth in frequencyshifted feedback fsf semiconductor lasers. Do this by locating the fpi as far away as you can while still obtaining. To avoid the inevitable drifts and to ensure longterm locking stability, it is useful to servo control the appropriate feedback phase and laser current relative to the reference cavity. Results from experimental studies using an 830 nm, qw, fabryperot cavity. The nonlinear laser equations can easily be solved. External ofb is recognized as a technique to increase mbw of directly modulated semiconductor lasers. The configuration employed allows for wider tunability than has been previously reported, allowing for easy tuning to the d1 or d2 line of 85 rb and 87 rb. Semiconductor optoelectronics farhan rana, cornell university p p p p np n v the number of photons leaving the cavity from the mirrors is therefore, p p p o p p o n n v the output power p of the laser is. The cavity with such a feedback method provides a robust starting mechanism for the pulse regime at any power above the laser threshold. The system considered here consists of a ld hlp 1400, a frequency discriminator ring cavity, roundtrip length cm, linewidth.
Dynamics of a semiconductor laser with frequency shifted feedback yoann noblet, joshua p. Although the fbg is similar to a mirror in perturbing the laser into chaos, it is not the same as a mirror because it provides spatially distributed reflections. Response of microchip solidstate laser to external frequency. We have constructed an external cavity diode laser ecdl with frequency shifted feedback fsf from an intracavity acoustooptic modulator aom that doubles the tuning range of similar lasers. Debarge, analysis of fr equency chirping of semiconductor lasers in the presence of. Infiltrated bunch of solitons in bidoped frequency. Frequency modulated microwave generation with feedback stabilization using an optically injected semiconductor laser junping zhuang,1 xiaozhou li,1 songsui li,1 and szechun chan1,2, 1department of electronic engineering, city university of hong kong, hong kong, china 2state key laboratory of millimeter waves, city university of hong kong. In contrast to previous theoretical predictions, it is found that the achievable bandwidth and a figure of merit, defined for maximizing the product of the bandwidth and output power for the fsf laser, are mainly determined by the spectral width. When a distributed feedback dfb semiconductor laser is driven below its lasing threshold, it behaves as a dfb semiconductor optical amplifier dfbsoa32. We report spectral features of a frequencyshiftedfeedback semiconductor laser with the antireflection coating of low reflectivity on the output facet. Comb generation bandwidth for frequencyshifted feedback. Selfinjected semiconductor distributed feedback lasers for.
The dynamics are mapped as a function of the level of frequency shifted feedback fsf and the injection current. Abstract dynamics of the output of a semiconductor laser with frequency shifted optical feedback system is systematically analyzed. Nonlinear optics can generate new lines from semiconductor lasers by harmonic generation and frequency mixing, but it requires high power, good beam quality, and narrow linewidth. Intensity noise in ultrahigh frequency modulated semiconductor laser with strong feedback and its influence on noise figure of rof links. Semiconductor laser diode outline this student project deals with the exam question semiconductor laser diode and covers the following questions. Semiconductor disk laser with frequencyshifted feedback. Dynamical origin of low frequency fluctuations in external. Optical feedback from scatterers suspended in fluid flow and rough bodies in motion consists of many, spectrally close, doppler shifted frequency components with random phase. Deflection measurement for bridges with frequencyshifted.
Lff 112, which takewx place when a semiconductor laser in biased close to the solitary laser threshold. Christiansen, bistability and lowfrequency fl uctuations in semiconductor lasers with optical feedback. Wide spectral width of frequency shifted feedback semiconductor laser. Schiellerup et al center frequency shift and reduction of feedback in lasers 289 s 150. Frequencyshifted optical feedback in a pumping laser diode dynamically amplified by a microchip laser. When tuning the laser frequency of a standard offtheshelf single section semiconductor laser by modulating the injection current, an inversion in the fm response occurs at a frequency that is typically on the order of one to a few mhz. Vallet a photonic oscillator, locked to a master rf synthesiser, was built by using a monolithic dualwavelength dfb semiconductor laser submitted to a frequency shifted optical feedback. 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. We broaden the linewidth of an external cavity diode laser using frequency shifted feedback from an intracavity acoustooptic modulator. Results from experimental studies using an 830 nm, qw, fabryperot cavity, semiconductor laser are reported. Frequency stabilization of semiconductor lasers by resonant optical feedback b. Lowspeed electronic feedback circuits are sufficient to accom plish this. Pdf dynamics of a semiconductor laser with frequency. Yariv department of applied physics, california institute of technology, mis 12895, pasadena, california 91125 received february 3, 1993.
Improved design of a frequencyshifted feedback diode laser. The laser was pumped through a wave length division multiplexer using a semiconductor disk laser at 20 nm with a maximum pump power of 1. The frequency shifted feedback laser fsf laser is an ultrahigh accuracy optical measurement technology which not only enables remotenoncontact measurement, but also has a maximum sampling frequency of hz. The phase synchronization of two semiconductor dfb lasers submitted to both frequency shifted crossinjection and self feedback is investigated, both numerically and experimentally. Analysis of frequency chirping of semiconductor lasers in the. The structure builds a onedimensional interference grating bragg scattering and the grating provides optical feedback for the laser. We report results on ranging based on frequency shifted feedback fsf lasers with two different implementations. Fsf pulse generation has been successfully demonstrated in nearir. Figure 2 shows the settling frequency of the laser versus tranverse position of the feedback beam in the crystal with respect to the position of the incident beam. To investigate the possibility of optical isolation of a semiconductor laser using acoustooptic interaction, the influence of frequency shifted feedback on a dfb laser was studied experimentally. Impact of the gain section profile on laser operation is shown. Extendedcavity semiconductor wavelengthswept laser for. Grenoble 1 cnrs, liphy umr 5588, grenoble, f38041, france corresponding author.
Although many peaks due to the chip mode were observed, a few peaks are connected each other without break showing a continuous spectral range wider than 100 ghz. We demonstrate ultrashort pulse generation from a fluoride fiber laser codoped with holmium and praseodymium. Frequency control of semiconductor lasers springerlink. Pulsed frequency shifted feedback laser for accurate long. We report spectral features of a frequency shifted feedback semiconductor laser with the antireflection coating of low reflectivity on the output facet. In conclusion, we have demonstrated an extendedcavity wavelengthswept semiconductor laser optimized for application to biomedical imaging. Mar 07, 2014 dynamics of the output of a semiconductor laser with frequency shifted optical feedback system is systematically analyzed. This paper presents the experimental studies on the allfiber frequency shifted feedback erbium laser.
The semiconductor fsf laser system operates without external injection seeding. The frequency chirping of a singlemode semiconductor laser in the presence of optical feedback is studied by rate equation analysis. In this case the key feature is frequency counting that allows convenient choice of either accuracy or speed of measurements simply by changing the duration of the interval during which the frequency is measured by counting. The laser output is divided into two parts by the beam splitter bs 1. The scheme also provides accurately controlled tuning of the stabilised laser frequency over a 50mhz range, as well as a simple method to frequency oset two external cavity diode lasers many gigahertz apart. Center frequency shift and reduction of feedback in. If a laser diode is directly modulated one obtains a modulation of the optical power and also a modulation of the optical frequency. Chaotic dynamics of a semiconductor laser subject to optical feedback from a frequency detuned fiber bragg grating fbg is investigated experimentally and numerically. The laser generates stable modelocked pulses of 29ps duration at a repetition rate of. Infiltrated bunch of solitons in bidoped frequencyshifted.
Frequencymodulated microwave generation with feedback. Semiconductor optoelectronics farhan rana, cornell university chapter distributed feedback dfb structures and semiconductor dfb lasers. We present a frequencyshifted feedback fsf laser based on a tapered ampli. To date, the majority of work focused on short pulse generation from this class of fiber laser has employed loss modulators in the cavity, both real and artificial. A large frequency modulation response of 350 mhzma. The frequency comb generates a beat frequency in a michelson interferometer, which is proportional to the path difference of a target and reference arm.
Efficient frequency noise reduction of gaaias laser diodes by. Semiconductor lasers and integrated devices 7 transient laser chirp modula tor chirp 0 1 2 0 21 0. With simple optical geometries a separate resonant fabryperot cavity can serve as an optical feedback element that forces a semiconductor laser automatically to lock its frequency optically to the cavity resonance. As an additional feature, its measurement accuracy is not dependent on the measurement distance. Periodic structures, like the dbr mirrors in vcsels, can be also realized in a waveguide, as shown. The laser operates as a coherent broadband source with up to 370ghz spectral width and 2. Stabilization and frequency control of a dfb laser with a. Consequently, the frequency shift totalled 160mhz in one round trip. A semiconductor laser is a very compact ligh t source 0. These include optical pumping of zeemansplit or dopplerbroadened alkalis, white light cooling 1, 2, and frequency comb generation. Kane department of physics and astronomy, macquarie university, sydney, australia. Improving the modulation bandwidth in semiconductor lasers. Electronic tunability from 1535 to 1580nm was measured.
Direct frequency modulation of vapor phase transported. Frequencymodulation characteristics of laser diodes. The influence of external frequency shifted feedback on a. For signal processing, some approaches based on a dfbsoa have been. Broadband laser light is useful for a variety of applications. The temporal behavior of a frequency shifted feedback laser is studied on a time scale comparable to the round trip transit time. In such a case, the power of the laser exhibits irregular dropout events at an average frequency that is about three orders of mag. A dedicated setup based on monolithic dfb lasers permits to effectively lock the frequency difference of the two lasers on an external reference over a broad range of. During this measurement it is important to minimize optical feedback into the laser. Pdf frequencyshifted optical feedback in a pumping. The rateequation model for a semiconductor laser under optical feedback is a useful tool for studying complex laser dynamics.
From 6 it can also be seen that the frequency shift will occur even for short cavity lasers such as monolithically integrated devices, if these are used in high bit rate fsk systems. The laser generates stable modelocked pulses of 29ps duration at a repetition rate of 300 mhz. Center frequency shift and reduction of feedback in directly. Mar 10, 2017 the laser was pumped through a wavelength division multiplexer using a semiconductor disk laser at 20 nm with a maximum pump power of 1. Synchronization of two dfb lasers using frequencyshifted. Nonlinear modification of the laser noise power spectrum. Oct 21, 2004 we report spectral features of a frequency shifted feedback semiconductor laser with the antireflection coating of low reflectivity on the output facet. Linewidth reduction and frequency stabilization of a semiconductor laser with a combination of fm sideband locking and optical feedback y. Shifting semiconductor laser wavelengths poses challenges. The frequency modulation fm due to injection current modulation of vapor phase transported distributed feedback vpt dfb semiconductor lasers is measured as a function of modulation frequency from 10 khz to 1 ghz. Selfinduced frequency scanning and distributed bragg. The frequency of the emitted light depends on the length of the optical cavity along the optical axis.
Dynamics of the output of a semiconductor laser with frequencyshifted optical feedback system is systematically analyzed. This method is used to stabilize laser frequencies and reduce linewidths by a factor of from 20 mhz to approximately 20 khz. Introduction a semiconductor laser is a very compact ligh t source 0. A novel frequency shifted feedback semiconductor disk laser cavity is proposed and experimentally verified. Frequency control of semiconductor lasers has become very important in recent years for several applications such as frequency standards, optical metrology. The isolation concept is based on a frequency shift of the laserlight by means of an acoustooptic bragg deflection. Drullinger national bureau of standards, boulder, colorado 80303 received may 20,1987.
Generation of a chirped comb with chirp rate of 85phzs across ghz from a frequency shifted feedback ring laser with semiconductor optical amplifier as gain medium is reported. Dynamics of a semiconductor laser with frequency shifted. Modeling of millimeterwave modulation characteristics of. In this letter, we alternatively employ a frequency shifting element. Linewidth reduction and frequency stabilization of a. Measure the shift of the laser frequency versus current. Ian mcmichael, monte khoshnevisan, and pochi yeh phase conjugation in semiconductor lasers, proc. The model includes the amplitudephasecoupling and spectralholeburning effects. Clockwise rotation of the adjustable mirror leads to a red shift. We present a frequency shifted feedback fsf laser based on a tapered ampli. Therefore, the intensity is modulated by these two. Osa ultrafast midinfrared fiber laser modelocked using. Theory of a frequencyshifted feedback laser article pdf available in optics communications 236. Tapered amplifier laser with frequencyshifted feedback.