13th International School on Quantum Electronics: Laser Physics and Applications, 2005
The purpose of this communication is to summarize and compare the results obtained under the proj... more The purpose of this communication is to summarize and compare the results obtained under the project" New all-optical systems and methods for magnetic and electromagnetic field measurement", financed by EC (contract G6RD-CT-2001-000642). The main aim of the ...
Proceedings of SPIE - The International Society for Optical Engineering, 2007
ABSTRACT In this communication we present our results related to examination of Coherent Populati... more ABSTRACT In this communication we present our results related to examination of Coherent Population Trapping resonance profile on the D1 line of 87Rb when coupling two ground-state Zeeman sublevels belonging to different hyperfine ground-state levels to a common excited-state one. For this, two coherent laser fields with frequency difference of about 6.8 GHz are used. The resonance is observed as a narrow dip in the fluorescence in dependence on the modulation frequency (fm) of the laser light, centered at 2fm = Deltavhf , where Deltavhf is the frequency difference between the ground-state hyperfine levels of Rb. The resonance observation and its splitting in 7 components have been demonstrated under influence of nonshielded laboratory magnetic field (MF). It has been shown that different components are with different sensitivity to the MF gradients that is in agreement with the performed estimations.
Comparative studies of MO resonances and MG responses with and without resonant laser irradiation... more Comparative studies of MO resonances and MG responses with and without resonant laser irradiation were carried out to establish the interconnection of the effects and the influence of the self-alignment destruction on the MO signal in positive column discharge. These studies aim to clarify the possible formation mechanisms of the neon 1 si (2p53s) states coherences and to examine the
We demonstrate how a pulsed two-wavelength tunable Ti:Al2O3 laser can operate at near maximum eff... more We demonstrate how a pulsed two-wavelength tunable Ti:Al2O3 laser can operate at near maximum efficiency, obtained in an optimized non-selective cavity. To achieve this efficiency we solve the intrinsic of the Passive Self- Injection Locking (PSIL) method problem of non-controlled free lasing at high pump level by combining the PSIL control with an appropriate dual-pulse pumping. Laser efficiency is increased
13th International School on Quantum Electronics: Laser Physics and Applications, 2005
We have characterized teh spectral properties and wavelength tuning behaviour of different types ... more We have characterized teh spectral properties and wavelength tuning behaviour of different types of diode lasers in order to evaluate their potential for applications in atomic spectroscopy and precision instruments. Here we report on studies of recently developed distributed feedback (DFB) and Fabry-Perot laser diodes, emitting around 780 and 795 nm, in solitary operation as well as in an extended-cavity
Tenth International School on Quantum Electronics: Laser Physics and Applications, 1999
ABSTRACT We report an original approach for tunable subnanosecond pulse (200 - 500 ps) generation... more ABSTRACT We report an original approach for tunable subnanosecond pulse (200 - 500 ps) generation in a ring dye laser. It is based on limitation of generation to a single `spike' from the starting transient process using for excitation a quasi- rectangular pulse with duration less or comparable with the time interval between the spikes. The pumping pulse (3 - 7 ns) is formed both by electrooptical division of a standard nanosecond (15 - 50 ns) pulse emitted by a Q-modulated laser in an original scheme and by overlapping of the obtained partial pulses which are fed bi-directionally into the active medium of the ring laser.
11th International School on Quantum Electronics: Laser Physics and Applications, 2001
ABSTRACT In the present work we report the results of the measurement of the angular distribution... more ABSTRACT In the present work we report the results of the measurement of the angular distribution of laser light reflected from a rough tooth surface and of Monte Carlo simulation of the 3-D process of photons migration in a two-layered human enamel- dentin structure. The measured reflected patterns are as a whole asymmetric and more spread than the calculated by the simulation. The measured total diffusely reflected power reaches 3 - 20% from the irradiating power. An increase in the total absorbed energy as well as in the spread of absorption is observed below the enamel-dentin interface. The scattering anisotropy affects in a different way the absorption below the tooth surface: the highly forward peaked phase function leads to decrease of absorption just below the air-enamel boundary and rise of absorption below the enamel-dentin boundary.
11th International School on Quantum Electronics: Laser Physics and Applications, 2001
ABSTRACT Here we report the proposed by us concept for monitoring the atmospheric and Earth Hg an... more ABSTRACT Here we report the proposed by us concept for monitoring the atmospheric and Earth Hg and Pb pollution by means of Intracavity Laser Spectroscopy (ILS). The concept profits from the extremely high sensitivity of the ILS dye laser registration by preliminary excitation of the Hg(Pb) atoms to a suitable level to induce absorption at the analytical transition corresponding to the second dye laser emission spectrum. A theoretical proof is given on the possibility for two-step optical excitation from the ground state level.
13th International School on Quantum Electronics: Laser Physics and Applications, 2005
The purpose of this communication is to summarize and compare the results obtained under the proj... more The purpose of this communication is to summarize and compare the results obtained under the project "New all-optical systems and methods for magnetic and electromagnetic field measurement", financed by EC (contract G6RD-CT-2001-000642). The main aim of the project is investigation of the potential of different approaches based on the effect of Coherent Population Trapping (CPT) for magnetic field measurement. The
Eighth International Conference on Laser and Laser Information Technologies, 2004
In this paper we present a detailed description of a method for reduction of the light shift in l... more In this paper we present a detailed description of a method for reduction of the light shift in laser-pumped gas-cell atomic clocks. The method consists in using a multi-frequency optical pumping obtained through frequency modulation of the laser spectrum with precisely controllable parameters. Experimental evidence of a strong reduction of the frequency dependence of the LS in an optical pumping
Summary: We report new experimental evidence of a magneto-galvanic (MG) effect in commercial holl... more Summary: We report new experimental evidence of a magneto-galvanic (MG) effect in commercial hollow cathode lamps (HCL). The goal of our investigation is to clarify the role of the neon 2p 5 3s configuration in the formation of the MG signals. Our results eloquently ...
We present, experimentally and theoretically, nonlinear magneto-optical rotation (NMOR) using two... more We present, experimentally and theoretically, nonlinear magneto-optical rotation (NMOR) using two spatially separated laser beams, the pump laser beam for creation and the probe laser beam for detection of the coherence between ground Zeeman sublevels. Both pump and probe lasers are tuned to Fg=2-->Fe=1 transition in R87b . With the specially designed spatial configuration of the pump and the probe
Journal of Physics B: Atomic, Molecular and Optical Physics, 2014
ABSTRACT The sub-natural width N-type resonance in a Λ-system, on the D2 line of Cs atoms is stud... more ABSTRACT The sub-natural width N-type resonance in a Λ-system, on the D2 line of Cs atoms is studied for the first time in the presence of a buffer gas (neon) and the radiations of two continuous narrow-band diode lasers. A L = 1 cm long cell is used to investigate the N-type process. The N-type resonance in a magnetic field for 133Cs atoms is shown to split into seven or eight components, depending on the magnetic field and laser radiation directions. The results obtained indicate that the levels Fg = 3, 4 are the initial and final ones in the N-resonance formation. The experimental results with magnetic field agree well with theoretical descriptions.
Dual-pulse pumping of PSIL-controlled Ti:Sapphire lasers: a technique for realization and control... more Dual-pulse pumping of PSIL-controlled Ti:Sapphire lasers: a technique for realization and control of the pumping. [Proceedings of SPIE 4397, 64 (2001)]. Dimitar G. Slavov. Abstract. We describe (computer analysis and experimental ...
Coherent Population Trapping resonances on the D line of Cs are examined under the influence of c... more Coherent Population Trapping resonances on the D line of Cs are examined under the influence of continuous and alternating magnetic fields. It is shown that alternating fields as low as a fraction of μT modifies significantly the shape of the resonances, which can be ...
Hanle absorption resonances with laser excitation of the neon 3s - 2p transition. [Proceedings of... more Hanle absorption resonances with laser excitation of the neon 3s - 2p transition. [Proceedings of SPIE 5226, 144 (2003)]. Vladimir A. Polischuk, Georgy C. Todorov, MP Chaika, Dimitar G. Slavov. Abstract. The lower level of laser ...
The resonant change of the discharge current with the application of an external magnetic field, ... more The resonant change of the discharge current with the application of an external magnetic field, known as magneto-galvanic effect (MGE), is studied as a galvanic manifestation of the atomic states coherence in a hollow cathode discharge. The signal measured represents the difference in the conductivity of the self-aligned and the non-aligned ensembles. The contribution of the metastable 1s5 and the
13th International School on Quantum Electronics: Laser Physics and Applications, 2005
The purpose of this communication is to summarize and compare the results obtained under the proj... more The purpose of this communication is to summarize and compare the results obtained under the project" New all-optical systems and methods for magnetic and electromagnetic field measurement", financed by EC (contract G6RD-CT-2001-000642). The main aim of the ...
Proceedings of SPIE - The International Society for Optical Engineering, 2007
ABSTRACT In this communication we present our results related to examination of Coherent Populati... more ABSTRACT In this communication we present our results related to examination of Coherent Population Trapping resonance profile on the D1 line of 87Rb when coupling two ground-state Zeeman sublevels belonging to different hyperfine ground-state levels to a common excited-state one. For this, two coherent laser fields with frequency difference of about 6.8 GHz are used. The resonance is observed as a narrow dip in the fluorescence in dependence on the modulation frequency (fm) of the laser light, centered at 2fm = Deltavhf , where Deltavhf is the frequency difference between the ground-state hyperfine levels of Rb. The resonance observation and its splitting in 7 components have been demonstrated under influence of nonshielded laboratory magnetic field (MF). It has been shown that different components are with different sensitivity to the MF gradients that is in agreement with the performed estimations.
Comparative studies of MO resonances and MG responses with and without resonant laser irradiation... more Comparative studies of MO resonances and MG responses with and without resonant laser irradiation were carried out to establish the interconnection of the effects and the influence of the self-alignment destruction on the MO signal in positive column discharge. These studies aim to clarify the possible formation mechanisms of the neon 1 si (2p53s) states coherences and to examine the
We demonstrate how a pulsed two-wavelength tunable Ti:Al2O3 laser can operate at near maximum eff... more We demonstrate how a pulsed two-wavelength tunable Ti:Al2O3 laser can operate at near maximum efficiency, obtained in an optimized non-selective cavity. To achieve this efficiency we solve the intrinsic of the Passive Self- Injection Locking (PSIL) method problem of non-controlled free lasing at high pump level by combining the PSIL control with an appropriate dual-pulse pumping. Laser efficiency is increased
13th International School on Quantum Electronics: Laser Physics and Applications, 2005
We have characterized teh spectral properties and wavelength tuning behaviour of different types ... more We have characterized teh spectral properties and wavelength tuning behaviour of different types of diode lasers in order to evaluate their potential for applications in atomic spectroscopy and precision instruments. Here we report on studies of recently developed distributed feedback (DFB) and Fabry-Perot laser diodes, emitting around 780 and 795 nm, in solitary operation as well as in an extended-cavity
Tenth International School on Quantum Electronics: Laser Physics and Applications, 1999
ABSTRACT We report an original approach for tunable subnanosecond pulse (200 - 500 ps) generation... more ABSTRACT We report an original approach for tunable subnanosecond pulse (200 - 500 ps) generation in a ring dye laser. It is based on limitation of generation to a single `spike' from the starting transient process using for excitation a quasi- rectangular pulse with duration less or comparable with the time interval between the spikes. The pumping pulse (3 - 7 ns) is formed both by electrooptical division of a standard nanosecond (15 - 50 ns) pulse emitted by a Q-modulated laser in an original scheme and by overlapping of the obtained partial pulses which are fed bi-directionally into the active medium of the ring laser.
11th International School on Quantum Electronics: Laser Physics and Applications, 2001
ABSTRACT In the present work we report the results of the measurement of the angular distribution... more ABSTRACT In the present work we report the results of the measurement of the angular distribution of laser light reflected from a rough tooth surface and of Monte Carlo simulation of the 3-D process of photons migration in a two-layered human enamel- dentin structure. The measured reflected patterns are as a whole asymmetric and more spread than the calculated by the simulation. The measured total diffusely reflected power reaches 3 - 20% from the irradiating power. An increase in the total absorbed energy as well as in the spread of absorption is observed below the enamel-dentin interface. The scattering anisotropy affects in a different way the absorption below the tooth surface: the highly forward peaked phase function leads to decrease of absorption just below the air-enamel boundary and rise of absorption below the enamel-dentin boundary.
11th International School on Quantum Electronics: Laser Physics and Applications, 2001
ABSTRACT Here we report the proposed by us concept for monitoring the atmospheric and Earth Hg an... more ABSTRACT Here we report the proposed by us concept for monitoring the atmospheric and Earth Hg and Pb pollution by means of Intracavity Laser Spectroscopy (ILS). The concept profits from the extremely high sensitivity of the ILS dye laser registration by preliminary excitation of the Hg(Pb) atoms to a suitable level to induce absorption at the analytical transition corresponding to the second dye laser emission spectrum. A theoretical proof is given on the possibility for two-step optical excitation from the ground state level.
13th International School on Quantum Electronics: Laser Physics and Applications, 2005
The purpose of this communication is to summarize and compare the results obtained under the proj... more The purpose of this communication is to summarize and compare the results obtained under the project "New all-optical systems and methods for magnetic and electromagnetic field measurement", financed by EC (contract G6RD-CT-2001-000642). The main aim of the project is investigation of the potential of different approaches based on the effect of Coherent Population Trapping (CPT) for magnetic field measurement. The
Eighth International Conference on Laser and Laser Information Technologies, 2004
In this paper we present a detailed description of a method for reduction of the light shift in l... more In this paper we present a detailed description of a method for reduction of the light shift in laser-pumped gas-cell atomic clocks. The method consists in using a multi-frequency optical pumping obtained through frequency modulation of the laser spectrum with precisely controllable parameters. Experimental evidence of a strong reduction of the frequency dependence of the LS in an optical pumping
Summary: We report new experimental evidence of a magneto-galvanic (MG) effect in commercial holl... more Summary: We report new experimental evidence of a magneto-galvanic (MG) effect in commercial hollow cathode lamps (HCL). The goal of our investigation is to clarify the role of the neon 2p 5 3s configuration in the formation of the MG signals. Our results eloquently ...
We present, experimentally and theoretically, nonlinear magneto-optical rotation (NMOR) using two... more We present, experimentally and theoretically, nonlinear magneto-optical rotation (NMOR) using two spatially separated laser beams, the pump laser beam for creation and the probe laser beam for detection of the coherence between ground Zeeman sublevels. Both pump and probe lasers are tuned to Fg=2-->Fe=1 transition in R87b . With the specially designed spatial configuration of the pump and the probe
Journal of Physics B: Atomic, Molecular and Optical Physics, 2014
ABSTRACT The sub-natural width N-type resonance in a Λ-system, on the D2 line of Cs atoms is stud... more ABSTRACT The sub-natural width N-type resonance in a Λ-system, on the D2 line of Cs atoms is studied for the first time in the presence of a buffer gas (neon) and the radiations of two continuous narrow-band diode lasers. A L = 1 cm long cell is used to investigate the N-type process. The N-type resonance in a magnetic field for 133Cs atoms is shown to split into seven or eight components, depending on the magnetic field and laser radiation directions. The results obtained indicate that the levels Fg = 3, 4 are the initial and final ones in the N-resonance formation. The experimental results with magnetic field agree well with theoretical descriptions.
Dual-pulse pumping of PSIL-controlled Ti:Sapphire lasers: a technique for realization and control... more Dual-pulse pumping of PSIL-controlled Ti:Sapphire lasers: a technique for realization and control of the pumping. [Proceedings of SPIE 4397, 64 (2001)]. Dimitar G. Slavov. Abstract. We describe (computer analysis and experimental ...
Coherent Population Trapping resonances on the D line of Cs are examined under the influence of c... more Coherent Population Trapping resonances on the D line of Cs are examined under the influence of continuous and alternating magnetic fields. It is shown that alternating fields as low as a fraction of μT modifies significantly the shape of the resonances, which can be ...
Hanle absorption resonances with laser excitation of the neon 3s - 2p transition. [Proceedings of... more Hanle absorption resonances with laser excitation of the neon 3s - 2p transition. [Proceedings of SPIE 5226, 144 (2003)]. Vladimir A. Polischuk, Georgy C. Todorov, MP Chaika, Dimitar G. Slavov. Abstract. The lower level of laser ...
The resonant change of the discharge current with the application of an external magnetic field, ... more The resonant change of the discharge current with the application of an external magnetic field, known as magneto-galvanic effect (MGE), is studied as a galvanic manifestation of the atomic states coherence in a hollow cathode discharge. The signal measured represents the difference in the conductivity of the self-aligned and the non-aligned ensembles. The contribution of the metastable 1s5 and the
Uploads
Papers by Dimitar Slavov