Ph.D. Student: Sagi Frishman
The electroholographic (EH) tunable laser is a laser whose wavelength of operation can be tuned over a wide spectral range by means of intracavity EH dispersive element.
The first experimental demonstration of the EH tunable laser was a fiber loop in which an erbium doped fiber amplifier (EDFA) was connected in series with a g44 EH grating constructed in a KLTN crystal. This is illustrated schematically in Figure 1. Electrical tunability over the entire C-band was demonstrated. Details of this demonstration are given in [REF10].
Figure 1: Schematic illustration of the first experimental demonstration of the electroholographic tunable laser.
In principle, an EH grating implemented in a KLTN crystal can be operated in the spectral range 400 nm - 5000 nm where the crystal is transparent. This provides wavelength tunability throughout the VIS-NIR spectral range.
Our current effort is to develop an EH tunable laser in a waveguide architecture employing ‘refractive index engineering’ as the fabrication methodology. Using a semiconductor optical amplifier as the gain medium will enable switching between wavelengths within less than 10 nanoseconds.