M.-C. Amann’s research while affiliated with Technical University of Munich and other places

... Extending the wavelength range to longer wavelengths presents significant challenges. As the wavelength increases, Auger recombination considerably reduces lasing efficiency [53], [54]. To extend the wavelength range into the mid-infrared above 3 µm, alternative material systems such as PbSe or PbTe [4], or different QW configurations such as type-II configurations, could be considered [55]. ...

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Optically pumped GaSb-based thin-disk laser design considerations for cw and dual-comb operation at a center wavelength around 2 μm

... The measured frequency response showed that the link BW is limited by the VCSEL and the real-time BER with PRBS7 at 80 Gb/s was below 7% HD-FEC threshold. This is the highest data rate demonstrated in real-time for a SM LW-VCSEL without complex offline DSP [29]. ...

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A Duobinary Approach Toward High-speed Short-reach Optical Interconnects

... [7][8][9][10] As an alternative to traditional THz QCLs, [7][8][9][10] THz sources based on intra-cavity difference-frequency generation (DFG) in mid-infrared (mid-IR, frequencies from 10 to 100 THz) QCLs have been developed and currently represent the only monolithic, electrically pumped semiconductor laser source technology able to generate coherent radiation in the 0.4-6 THz band at room temperature. [11][12][13][14] THz DFG-QCLs use an active region designed for broad mid-IR gain [15][16][17] to permit simultaneous lasing in two mid-IR modes, which are spaced by the desired THz frequency. The device's active region is also designed to possess a strong second-order nonlinear response χ (2) for THz DFG. ...

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Phase-matching in terahertz quantum cascade laser sources based on Cherenkov difference-frequency mixing

... 18 There are also few studies focusing on the transient thermal effects in semiconductor lasers. 19,20 Size scalability of micro-and nanocavity lasers is another important consideration as wavelength-and sub-wavelength scale lasers have been pursued to realize smaller footprints, lower lasing thresholds, and higher modulation speeds, giving rise to non-classical phenomena which are hardly seen in conventional resonators, such as the Purcell effect (enhancement of the spontaneous emission rate) and high β-factor (spontaneous emission coupling to the lasing mode). 21−23 Furthermore, size scaling leads to an increased effect of thermal interfaces that needs to be taken into account. ...

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Thermal Simulation and Experimental Analysis of Optically Pumped InP-on-Si Micro- and Nanocavity Lasers

... Vertical-cavity surface-emitting lasers (VCSELs) have become technologically mature and highly sophisticated optoelectronic emitters. They are nowadays one of the most important semiconductor lasers, dominating the high-speed datacom [1] and sensing markets [2]. Among others, quantum optic applications, such as atomic clocks [3] and quantum gyroscopes [4], represent a hot topic. ...

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On-demand polarization by a vertical-cavity surface-emitting laser with two tilted sub-wavelength gratings

... Compared with the first two types of vdWHs, type-III heterostructures are relative rare. Due to the unique band alignment, the electrons in the type-III vdWHs are prone to transfer from the valence band (VB) of one 2D material to the conduction band (CB) of another, which is desirable for improving the electron tunneling efficiency in TFETs through band-to-band tunneling transport mechanism [79][80][81][82]. ...

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Optoelectronic Properties and Applications of Two-Dimensional Layered Semiconductor Van der Waals Heterostructures: Perspective from Theory

... For the pristine VCSEL device, increasing the forward current will increase the peak wavelength at which the laser emits most of its power. 37 The output power of a VCSEL is proportional to the current density in the active region. This is because the current density determines the number of carriers that are injected into the active region. ...

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Effect of High Current Density Pulses on Performance Enhancement of Optoelectronic Devices

... 28-31, involves the use of an air gap within the DBR to attain a significant contrast in the refractive index of the DBR layers. Alternatively, another strategy to address this challenge is the exploration of more intricate compound materials [32,33]. ...

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Development of the hybrid distributed Bragg reflectors for mid-infrared applications

... We observed a spectral distinguishability of the four off-the-shelf VCSELs due to fabrication imperfections, however, for our proof-of-principle demonstration we accept this open side channel. When commercializing such systems in the future, this could be avoided, e.g., by proper selection of the diodes prior to the assembly of the module [39], by the use of microelectromechanical system (MEMS)-tunable structures [41,42] or by spectral filtering once the spectra of the four diodes start overlapping. ...

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Quantum key Distribution with a Hand-Held Sender Unit

... These conventional fire detection methods can achieve acceptable FNR, but are susceptible to non-fire interference sources resulting in high FPR. For example, water vapor, dust and even insects can cause smoke detectors to trigger false alarms [4]. Frequent alarms caused by fire misinformation will waste a lot of social resources and erode people's sense of urgency and crisis. ...

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A new multi-sensor fire detection method based on LSTM networks with environmental information fusion