| 1. |
- Alnis, Janis, et al.
(författare)
-
Laser spectroscopy of free molecular oxygen dispersed in wood materials
- 2003
-
Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 77:6-7, s. 691-695
-
Tidskriftsartikel (refereegranskat)abstract
- The recently introduced Gas in Scattering Media Absorption Spectroscopy (GASMAS) technique is applied to the study of various wood samples. Molecular oxygen in the pores of the strongly scattering material is detected using diode laser spectroscopy around 760 nm. Diffuse light propagation in these media is studied by time-dispersion measurements. Furthermore, anisotropy related to the fibre structure of wood and gas diffusion properties are studied. Promising extensions of the experiments are discussed.
|
|
| 2. |
- Murnieks, Rihards, et al.
(författare)
-
Silica micro-rod resonator-based Kerr frequency comb for high-speed short-reach optical interconnects
- 2023
-
Ingår i: Optics Express. - : Optica Publishing Group. - 1094-4087. ; 31:12, s. 20306-20320
-
Tidskriftsartikel (refereegranskat)abstract
- Conventional data center interconnects rely on power-hungry arrays of discrete wavelength laser sources. However, growing bandwidth demand severely challenges ensuring the power and spectral efficiency toward which data center interconnects tend to strive. Kerr frequency combs based on silica microresonators can replace multiple laser arrays, easing the pressure on data center interconnect infrastructure. Therefore, we experimentally demonstrate a bit rate of up to 100 Gbps/& lambda; employing 4-level pulse amplitude modulated signal transmission over a 2 km long short-reach optical interconnect that can be considered a record using any Kerr frequency comb light source, specifically based on a silica micro-rod. In addition, data transmission using the non-return to zero on-off keying modulation format is demonstrated to achieve 60 Gbps/& lambda;. The silica micro-rod resonator-based Kerr frequency comb light source generates an optical frequency comb in the optical C-band with 90 GHz spacing between optical carriers. Data transmission is supported by frequency domain pre-equalization techniques to compensate amplitude-frequency distortions and limited bandwidths of electrical system components. Additionally, achievable results are enhanced with offline digital signal processing, implementing post-equalization using feed-forward and feedback taps.
|
|
| 3. |
- Murnieks, Rihards, et al.
(författare)
-
Silica micro-rod resonator-based Kerr frequency comb for high-speed short-reach optical interconnects.
- 2023
-
Ingår i: Optics Express. - : Optical Society of America. - 1094-4087. ; 31:12, s. 20306-20320
-
Tidskriftsartikel (refereegranskat)abstract
- Conventional data center interconnects rely on power-hungry arrays of discrete wavelength laser sources. However, growing bandwidth demand severely challenges ensuring the power and spectral efficiency toward which data center interconnects tend to strive. Kerr frequency combs based on silica microresonators can replace multiple laser arrays, easing the pressure on data center interconnect infrastructure. Therefore, we experimentally demonstrate a bit rate of up to 100 Gbps/λ employing 4-level pulse amplitude modulated signal transmission over a 2 km long short-reach optical interconnect that can be considered a record using any Kerr frequency comb light source, specifically based on a silica micro-rod. In addition, data transmission using the non-return to zero on-off keying modulation format is demonstrated to achieve 60 Gbps/λ. The silica micro-rod resonator-based Kerr frequency comb light source generates an optical frequency comb in the optical C-band with 90 GHz spacing between optical carriers. Data transmission is supported by frequency domain pre-equalization techniques to compensate amplitude–frequency distortions and limited bandwidths of electrical system components. Additionally, achievable results are enhanced with offline digital signal processing, implementing post-equalization using feed-forward and feedback taps.
|
|
| 4. |
- Salgals, Toms, et al.
(författare)
-
Silica Microsphere WGMR-Based Kerr-OFC Light Source and Its Application for High-Speed IM/DD Short-Reach Optical Interconnects
- 2022
-
Ingår i: Applied Sciences. - : MDPI AG. - 2076-3417. ; 12:9, s. 4722-
-
Tidskriftsartikel (refereegranskat)abstract
- Kerr optical frequency combs (OFCs) based on silica microsphere whispering gallery mode resonator (WGMR) have various applications where they are used as a light source. For telecommunication purposes, WGMR-based Kerr-OFC comb generators can be physically realized using silica microsphere resonators and can be used to replace multiple laser arrays. In such a realization, these novel light sources have the potential to demonstrate an attractive solution for intra-datacenter interconnects (DCI). In this paper, we show an experimental demonstration of a silica microsphere WGMR-based Kerr OFC light source where newly generated 400 GHz spaced carriers together with powerful linear equalization techniques, such as a linear symbol-spaced adaptive decision-feedback equalizer (DFE) with feed-forward (FF) and feedback (FB) taps, provide an alternative to individual lasers ensuring low-cost and low-complexity IM/DD scheme for the transmission of NRZ-OOK modulated signals at data rates up to 50 Gbps/lambda over 2 km SMF link. Finally, we demonstrate a record 50 Gbps per lambda transmission of NRZ-OOK modulated signals with a novel silica microsphere WGMR-based Kerr-OFC as a light source operating in the optical C-band, surpassing the previously demonstrated data rate record by five times.
|
|
| 5. |
- Sjöholm, Mikael, et al.
(författare)
-
Gas transport in wood assessed by laser spectroscopy
- 2003
-
Ingår i: 2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666). - 0780377346 ; , s. 505-505
-
Konferensbidrag (refereegranskat)abstract
- The Gas in scattering media absorption spectroscopy (GASMAS) technique provides new opportunities to nondestructively study gas in highly scattering natural and man-made porous materials. In this paper, we report applications of the GASMAS method on wood samples using diode-laser-based spectroscopy on molecular oxygen. And the integrated oxygen absorption for wood of different densities and the anisotropy related to the fibre structure was also investigated
|
|
