Rainer Martini | Stevens Institute of Technology (original) (raw)

Papers by Rainer Martini

Laser in Forschung und Technik / Laser in Research and Engineering, 1996

We report a frequency-stabilized CO-overtone laser system for precision spectroscopy applications... more We report a frequency-stabilized CO-overtone laser system for precision spectroscopy applications. The laser frequency is stabilized in a frequency-offset locking scheme (FOL) on combination frequencies of two CO2 laser standards. This FOL technique allows us to sweep the laser frequency in a well-defined and linear manner with very high frequency accuracy. The uncertainty is smaller than 40 kHz (corresponding to Δv/v=4·10-10 at v=100 THz). This stabilized laser system enables us to record line shapes of molecular saturation signals in a computer-controlled experiment.

A combination of scattering and scintillation effects is considered to compare the resilience of ... more A combination of scattering and scintillation effects is considered to compare the resilience of mid-IR and near-IR free space communication links. Beam-wander rw(t) under different scintillation conditions for mid-IR and near- IR beams are recorded simultaneously in real-time by a unique broad-band camera. The correlation coefficients show that both beams undergo the same pathway and experience the same scattering and scintillation effect which allows to identify and distill wavelength dependent effects. Using the frequency dependence in the observed beam wander allows for classification of our simulated atmospheric turbulence. Under these lab conditions, perceived refractive index structure parameter C_n^2 is extracted for each wavelength and a long-term radius is estimated for a long-distance link. In addition, the transmissivity and broadening of beams are calculated using discrete ordinate method to account for the scattering by fog. Considering both scattering and scintillatio...

Electro-Optical (EO) and Infra-Red (IR) sensors have been jointly deployed in many surveillance s... more Electro-Optical (EO) and Infra-Red (IR) sensors have been jointly deployed in many surveillance systems. In this work we study the special characteristics of optical flow in IR imagery, and introduce an optical flow estimation method using co-registered EO and IR image frames. The basic optical flow calculation is based on the combined local and global (CLG) method

Summary form only given. In summary, we demonstrate the application of the external electro optic... more Summary form only given. In summary, we demonstrate the application of the external electro optical (EO)-sampling method for spatial mapping of electric near-field patterns on planar resonators. Using this method we gain important information about the local behavior of the resonant structure.

Plasma Processes and Polymers

Bulletin of the American Physical Society, 2006

Submitted for the MAR06 Meeting of The American Physical Society A New All-Optical Imaging Scheme... more Submitted for the MAR06 Meeting of The American Physical Society A New All-Optical Imaging Scheme based on QWIP technology DEBING ZENG, GANG CHEN, RAINER MARTINI, Dept. of Physics and Engr. Physics, Stevens Institute of Technology — Infrared imaging applications have gained increasing interest over the recent decades due to favorable light propagation, night imaging as well as chemical sensing applications. However, the scalability of the existing techniques towards high resolution in the multi-megapixel range is one of the major challenges in today’s IR imaging technologies. Here we present an alternative solution using an all-optical wavelength conversion scheme. QWIP has been successfully proven their potential in IR imaging applications. Yet the fundamental conversion process from IR light to electric current has been one of the major restrictions in such system. To overcome this problem we propose the use of an all-optical conversion scheme, which utilizes an interband resonant...

We identify a weather-proof channel for quantum communications using 3950 nm photons, and report ... more We identify a weather-proof channel for quantum communications using 3950 nm photons, and report on their generation and detection via parametric conversion with a measured coincidence to accidental ratio of 54±7 and spectral brightness of 4.4×102 pair/s/nm/mW.

Superlattices and Microstructures, 1999

International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, 2011

ABSTRACT In the past two decades, there is an increasing interest in developing new infrared phot... more ABSTRACT In the past two decades, there is an increasing interest in developing new infrared photodetectors based on novel nanostructures, such as quantum well infrared photodetector (QWIP) and quantum dot infrared photodetector (QDIP). However, the commonly used electrical read-out approach limits the resolution of QWIP/QDIP infrared imaging to around 1 mega pixel. In this paper, we reported our theoretical study on an all-optical readout based on quantum dot phase modulation, which provides a new way for the intersubband infrared detection by measuring the phase change in the transmitted interband near infrared (NIR) and allows a high-resolution middle infrared (MIR) or far infrared (FIR) imaging. Utilizing the long life time in the quantum dots, the intersubband infrared resonant light is used to control the interband NIR resonant light phase. An infrared image can be converted into a visible or near infrared image, which can be easily captured with a high resolution CCD camera. It provides a new way to obtain a high resolution infrared image.

Novel In-Plane Semiconductor Lasers XIII, 2014

ABSTRACT Based on the nature of ultra-fast carrier life time in semiconductor quantum well, optic... more ABSTRACT Based on the nature of ultra-fast carrier life time in semiconductor quantum well, optical modulation of quantum cascade laser offers an unique way to control intersubband transition through interband transition. This method circumvents the problem of parasitic effects associated with electrical modulation, resulting in a high modulation bandwidth. In addition it allows for fast wavelength modulation on standard type quantum cascade lasers by directly injecting charge carriers to laser active region with near-infrared optical excitation. Here, we demonstrate the first infrared spectroscopic measurement conducted with this all-optical modulation approach. Using wavelength modulation spectroscopy, a 1st order derivative spectrum of methanol vapor gas is observed. Optically based wavelength modulation up to 200 MHz is purely induced by pumping the front facet of quantum cascade laser with an intensity-modulated 1550 nm DFB laser. Compared with conventional direct absorption approach, the noise equivalent sensitivity is improved by a factor of 10 by adding optical modulation in a non-optimized system.

Laser in Forschung und Technik / Laser in Research and Engineering, 1996

We report a frequency-stabilized CO-overtone laser system for precision spectroscopy applications... more We report a frequency-stabilized CO-overtone laser system for precision spectroscopy applications. The laser frequency is stabilized in a frequency-offset locking scheme (FOL) on combination frequencies of two CO2 laser standards. This FOL technique allows us to sweep the laser frequency in a well-defined and linear manner with very high frequency accuracy. The uncertainty is smaller than 40 kHz (corresponding to Δv/v=4·10-10 at v=100 THz). This stabilized laser system enables us to record line shapes of molecular saturation signals in a computer-controlled experiment.

A combination of scattering and scintillation effects is considered to compare the resilience of ... more A combination of scattering and scintillation effects is considered to compare the resilience of mid-IR and near-IR free space communication links. Beam-wander rw(t) under different scintillation conditions for mid-IR and near- IR beams are recorded simultaneously in real-time by a unique broad-band camera. The correlation coefficients show that both beams undergo the same pathway and experience the same scattering and scintillation effect which allows to identify and distill wavelength dependent effects. Using the frequency dependence in the observed beam wander allows for classification of our simulated atmospheric turbulence. Under these lab conditions, perceived refractive index structure parameter C_n^2 is extracted for each wavelength and a long-term radius is estimated for a long-distance link. In addition, the transmissivity and broadening of beams are calculated using discrete ordinate method to account for the scattering by fog. Considering both scattering and scintillatio...

Electro-Optical (EO) and Infra-Red (IR) sensors have been jointly deployed in many surveillance s... more Electro-Optical (EO) and Infra-Red (IR) sensors have been jointly deployed in many surveillance systems. In this work we study the special characteristics of optical flow in IR imagery, and introduce an optical flow estimation method using co-registered EO and IR image frames. The basic optical flow calculation is based on the combined local and global (CLG) method

Summary form only given. In summary, we demonstrate the application of the external electro optic... more Summary form only given. In summary, we demonstrate the application of the external electro optical (EO)-sampling method for spatial mapping of electric near-field patterns on planar resonators. Using this method we gain important information about the local behavior of the resonant structure.

Plasma Processes and Polymers

Bulletin of the American Physical Society, 2006

Submitted for the MAR06 Meeting of The American Physical Society A New All-Optical Imaging Scheme... more Submitted for the MAR06 Meeting of The American Physical Society A New All-Optical Imaging Scheme based on QWIP technology DEBING ZENG, GANG CHEN, RAINER MARTINI, Dept. of Physics and Engr. Physics, Stevens Institute of Technology — Infrared imaging applications have gained increasing interest over the recent decades due to favorable light propagation, night imaging as well as chemical sensing applications. However, the scalability of the existing techniques towards high resolution in the multi-megapixel range is one of the major challenges in today’s IR imaging technologies. Here we present an alternative solution using an all-optical wavelength conversion scheme. QWIP has been successfully proven their potential in IR imaging applications. Yet the fundamental conversion process from IR light to electric current has been one of the major restrictions in such system. To overcome this problem we propose the use of an all-optical conversion scheme, which utilizes an interband resonant...

We identify a weather-proof channel for quantum communications using 3950 nm photons, and report ... more We identify a weather-proof channel for quantum communications using 3950 nm photons, and report on their generation and detection via parametric conversion with a measured coincidence to accidental ratio of 54±7 and spectral brightness of 4.4×102 pair/s/nm/mW.

Superlattices and Microstructures, 1999

International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, 2011

ABSTRACT In the past two decades, there is an increasing interest in developing new infrared phot... more ABSTRACT In the past two decades, there is an increasing interest in developing new infrared photodetectors based on novel nanostructures, such as quantum well infrared photodetector (QWIP) and quantum dot infrared photodetector (QDIP). However, the commonly used electrical read-out approach limits the resolution of QWIP/QDIP infrared imaging to around 1 mega pixel. In this paper, we reported our theoretical study on an all-optical readout based on quantum dot phase modulation, which provides a new way for the intersubband infrared detection by measuring the phase change in the transmitted interband near infrared (NIR) and allows a high-resolution middle infrared (MIR) or far infrared (FIR) imaging. Utilizing the long life time in the quantum dots, the intersubband infrared resonant light is used to control the interband NIR resonant light phase. An infrared image can be converted into a visible or near infrared image, which can be easily captured with a high resolution CCD camera. It provides a new way to obtain a high resolution infrared image.

Novel In-Plane Semiconductor Lasers XIII, 2014

ABSTRACT Based on the nature of ultra-fast carrier life time in semiconductor quantum well, optic... more ABSTRACT Based on the nature of ultra-fast carrier life time in semiconductor quantum well, optical modulation of quantum cascade laser offers an unique way to control intersubband transition through interband transition. This method circumvents the problem of parasitic effects associated with electrical modulation, resulting in a high modulation bandwidth. In addition it allows for fast wavelength modulation on standard type quantum cascade lasers by directly injecting charge carriers to laser active region with near-infrared optical excitation. Here, we demonstrate the first infrared spectroscopic measurement conducted with this all-optical modulation approach. Using wavelength modulation spectroscopy, a 1st order derivative spectrum of methanol vapor gas is observed. Optically based wavelength modulation up to 200 MHz is purely induced by pumping the front facet of quantum cascade laser with an intensity-modulated 1550 nm DFB laser. Compared with conventional direct absorption approach, the noise equivalent sensitivity is improved by a factor of 10 by adding optical modulation in a non-optimized system.