The design of application-specific integrated circuit (ASIC) is at the core of modern ultra-high-speed transponders employing advanced digital signal processing (DSP) algorithms. This manuscript discusses the motivations for jointly utilizing transmission techniques such as probabilistic shaping and digital sub-carrier multiplexing in digital coherent optical transmissions systems. We firstly report the key-building blocks of high-speed modern DSP-based transponders working up to 800G per wave. Secondly, we show the benefits of these transmission methods in terms of system level performance. Finally, we report, to the best of our knowledge, the first long-haul experimental transmission -e.g., over 1000 km -with a real-time 7 nm DSP ASIC and digital coherent optics (DCO) capable of data rates up to 1.6 Tb/s using two waves (2×800G).

No abstract

High resolution infrared emission spectra have been measured for AuH and AuD and for two isotopomers of each of CuH, CuD, AgH, and AgD. The molecules were made in a carbon tube furnace ͑King furnace͒, and in spite of intense background thermal emission from the furnace ͑at Ͼ2000°C͒, vibration-rotation emission data could be recorded. Together with high resolution measurements taken from the literature, the data for each species were treated using two types of combined-isotopomer analysis: One based on fits to empirical molecular parameters, and the other based on direct fits to the underlying potential energy functions, both of which take account of mass-dependent Born-Oppenheimer breakdown correction terms. Accurate isotopically related Dunham parameters and Born-Oppenheimer breakdown parameters are obtained for each species, as well as accurate analytic potential functions and adiabatic and nonadiabatic radial correction functions.

The high resolution spectrum of the 0 0 0 vibronic band of the C 2 A 1 -X 2 A 1 transition of CaNH 2 was recorded with a laser ablation/supersonic molecular beam spectrometer. Approximately 140 lines of the K a Јϭ0←K a Љϭ0 and the K a Јϭ1←K a Љϭ1 sub-bands were measured and combined with the previous à 2 B 2 -X 2 A 1 and B 2 B 1 -X 2 A 1 results. A global fit of the data was carried out and the effective spectroscopic constants for the X, Ã, B, C states are reported. A complete set of spinrotation constants (⑀ ␣␣ 's͒ are now available for the à 2 B 2 , B 2 B 1 and C 2 A 1 states. The unpaired electron in these three excited states can be considered to be located in three p -orbitals (p x ,p y ,p z ) centered on the metal atom. The simple pure precession model provides estimates for the 9 spin-rotation parameters in the Ã, B, and C states.

No abstract