SBIR Phase I:Orthogonal Frequency/Amplitude Modulation of a Laser Oscillator

This Small Business Innovation Research (SBIR) Phase I project proposes the development of a laser source which can accommodate frequency and amplitude modulation and which combines a high degree of linearity and efficiency with AM/FM orthogonality, i.e., which exhibits little or no coupling (cross-talk) between the two modes of modulation. Together with low phase noise, the requirement for amplitude/frequency modulation orthogonality is paramount in applications that require the generation of arbitrary independent amplitude and phase waveforms. The heart of our proposed diode-pumped solid-state laser source is a compact fiber-coupled optical resonator that contains a unique intracavity electro-optic birefringent filter. Use of this novel filter technology permits us to control independently the optical carrier wavelength, the frequency and/or modulation depth of an impressed FM signal, and the modulation amplitude of the output coupled laser intensity. During the Phase I program, we intend to demonstrate basic Design principles by characterizing the FM and AM response of a prototypical laser. This will validate all high-risk elements of the concept and will provide the data necessary for completing and implementing the composite design, which is envisioned for the Phase II program. The proposed effort will lead to the development of a family of application-specific lasers that are based on the same core technology. Products we see emerging in the near future from these efforts include rapidly wavelength-settable lasers with narrow linewidth, and fast, broad tuning lasers with multifunctional modulation capability. These lasers are based upon a similar, low-cost, fiber-coupled solid-state design, which employs self-aligning resonator concepts together with precision electro-optic manufacturing and packaging techniques. In the special case of lasers, which operate at 1550 nm, the technology is directly applicable to optical networks, wireless communications, telecommunications, phased array radar, precision metrology, LIDAR, and optical fiber sensors for acoustic and seismic sensing. We expect that the main customers for our technology will initially be those involved in niche areas (sensors, phased array radar, research, etc.), and, as the product matures, eventually shift to those involved in more commercially attractive markets, such as optical communications in metro and cable networks.