POLIMI DEI CREW

CREW-Project - Group POLIMI Dipartimento di Elettronica e Informazione and CNR-CSTS Research Center Milan – IT R&D performer in WP2: 

CREW-Project - Group POLIMI Dipartimento di Elettronica e Informazione and CNR-CSTS Research Center Milan – IT   R&D performer in WP2 Politecnico di Milano Project Management meeting, Milan January 28th–29th 2002

Outline: 

Outline Welcome and information POLIMI Working-Group and its Activities for the CREW Project The “Politecnico di Milano”

The “Politecnico di Milano”: 

The “Politecnico di Milano” The oldest university of Milan, reaching this year its 140th Academic Year It is structured into 5 Faculties of Engineering and 3 Faculties of Architecture Offers 26 studying path in 6 cities Working staff is more than 1000 teachers and researchers About 40.000 students coming from all italian regions and from abroad; more than 7.000 are the first year students

Head and Branch Sites of Politecnico: 

Head and Branch Sites of Politecnico Dept. of Electronics and Information Bachelor, Master, and PhD degrees in Electronics, Information Science, and Telecommunication Several research activities, including Optical Communications and Optical Metrology

POLIMI Working-Group: 

POLIMI Working-Group Prof. Cesare SVELTO Prof. Elio BAVA Dr. Gianluca GALZERANO Fabio FERRARIO Optical Frequency Metrology 532nm and 1064nm Standards 1.5mm for Optical Fiber Communications 2.1mm References for DIAL, LIDAR, and metrology

532nm-1064nm, and 2.1mm Standards: 

532nm-1064nm, and 2.1mm Standards Frequency-doubled Nd:YAG laser locked to I2 lines at 532nm (Stability 10-14 , Accuracy 10-12) Realization of the meter, high-resolution sensors, high-resolution spectroscopy, and space comm. Diode-pumped Tm-Ho:YAG laser locked to HBr, CO2, and H2O lines around 2.1mm (Stability 10-9 ) DIAL and LIDAR systems, eye-safe systems, metrology, and medical applications

1.5mm for Optical Fiber Communications: 

1.5mm for Optical Fiber Communications Novel diode-pumped Er-Yb:glass laser at 1.5mm Single frequency, linear polarization, and diffraction limited output beam, wide tunability, low frequency and amplitude noise Frequency stabilization experiments Er-Yb:glass laser locked to saturated 39K D1 line at 770.1nm (Stability 10-12) Er-Yb:glass laser locked to 12C2H2 and 13C2H2 lines around 1.54mm (Stability 10-10)

1.5mm Diode-Pumped Er-Yb:glass Laser: 

1.5mm Diode-Pumped Er-Yb:glass Laser

Er-Yb:glass Laser (Wavelength/Frequency): 

Er-Yb:glass Laser (Wavelength/Frequency) wavelength tuning: up to 36nm (etalon) frequency control: 15kHz bandwidth (PZT) short-term stability: 1-ms linewidth of 50kHz

Er-Laser + SHG / 39K Standard (experiment): 

Er-Laser + SHG / 39K Standard (experiment) Efficient PPLN waveguide frequency doubler 380%W-1 internal conversion efficiency 18WSH

Er-Laser + SHG / 39K Standard (stability results): 

Er-Laser + SHG / 39K Standard (stability results) 0.5kHz stability over 1s 20kHz peak-to-peak fluctuations in 200s period

Er-Laser + 13C2H2 [Doppler](stabilization experiments): 

Er-Laser + 13C2H2 [Doppler] (stabilization experiments) 20kHz stability over 1s Simple fringe-side locking technique

Er-Laser + 13C2H2 [saturated](experimental set-up): 

Er-Laser + 13C2H2 [saturated] (experimental set-up)

Er-Laser + 13C2H2 [saturated](spectroscopy): 

Er-Laser + 13C2H2 [saturated] (spectroscopy) Saturation Dip: 7% contrast and 1.2MHz width

Next Developments: 

Next Developments Frequency stabilization of Er-Yb:glass laser against saturated 13C2H2 lines Characterization of the laser frequency stability Linear spectroscopy of HI around 1.54mm Characterization of HI pressure broadening Characterization of HI pressure shift Validation of HI cells durability

Work done: 

Work done 10 aluminum mounts for the Er-Yb laser cavity Drawings of the new pieces Acquisition of different mechanical parts Consumables for the Er laser 20 Er-Yb:glass coated active media 2 etalon (R=10% L=40m) 8 output coupling mirrors (RoC=-40mm) 2 special mirrors for laser action at 1556nm 2 fiber-coupled 975nm 1W pump diodes from OPC 15 quartz cells 100mm long Ordered from Hellma mod. QS-225 (nov. 2001) Delivered to IMGC for filling with HI (dec. 2001) 1 extended-cavity laser diode (5mW 1530-1565nm)

Work to be done (in progress): 

Work to be done (in progress) Characterization of the tunable diode laser Optical power, wavelength, spatial profile, tuning coefficient and range Linewidth (beat note with IMGC and Er-Yb:glass lasers) Measurements on HI cells (sealed at different pressures) Doppler profiles and line widths Pressure shifts of line center Durability with light and time Frequency stabilization to HI Doppler lines Fringe-side locking on 1 and 2 sides of the profile Wavelength modulation and 1st harmonic locking Error signal analysis: stability (p-p and rms) and Allan Beat note measurements: Allan, accuracy estimates

Conclusions: 

Conclusions