SBIR-STTR Award

To address the Navy need, Physical Optics Corporation (POC) proposes to develop an innovative Self-Mixing Laser Anemometer (SMILA). This proposed system is based on intensity variation due to self-mixing interference in a diode laser cavity. The innovation in assembling three diode lasers in a specific geometry enables SMILA to measure three-component airflow velocity regardless of the relative angle between the laser and the direction of airflow. SMILA uses several individual flow velocity measurement modules mounted on a mast at two different locations away from the volume of interest. Each module measures three-component velocities within a wind cell volume of 200 ft x 160 ft x 2 ft. Consequently, the SMILA system will be capable of concurrently measuring three-component airflow velocities throughout the entire volume of interest (400 ft x 160 ft x 40 ft) with spatial and frequency resolutions of 2 ft and 20 Hz, respectively. In Phase I, POC will demonstrate the feasibility of the SMILA system with one velocity measuring module to measure three-component velocities of airflow in a laboratory. In Phase II, POC plans to develop a shipboard-deployable SMILA prototype to be installed and tested in a Navy ship or similar platform recommended by the Navy.

Benefit:
Both military and civilian sectors will benefit from the successful development of the SMILA system. Defense agencies will have a highly reliable, small size, electromagnetic interference free optical technology to accurately profile airflow fields in the vicinity of a full-scale rotorcraft operating near a ships deck. Velocity data from SMILA will help conduct a full-scale study of the aerodynamics of shipboard rotorcraft operations and to successfully implement shipboard aircraft advanced vertical lift operations. Commercial applications of SMILA include wind flow monitoring near civil structures, other buildings, and wind turbines, and analysis of rotor downwash on personnel and parked aircraft at airports and building helipads. SMILA can also be used to provide real-time wind velocity information for guided projectiles to autonomously correct their trajectories.

Keywords:
optical, optical, Rotorcraft, Downwash, Shipboard, Airwake, Self-Mixing, velocity, LIDAR, Flowfield

To address the Navys need for a system to measure three-component airflow velocities in the vicinity of full-scale helicopters, Physical Optics Corporation (POC) has developed and demonstrated an innovative Self-Mixing Laser Anemometer (SMILA) prototype. This proposed system is based on the self-mixing interference in a diode laser cavity. The innovative use of high-power semiconductor diode lasers in a non-coplanar geometry enables the SMILA system to measure three-component velocity of airflow in open airspace. In Phase I, POC demonstrated the feasibility of the SMILA system by measuring the velocity of unidirectional airflow in a laboratory environment with accuracy of within 2% in the velocity range 04 miles per hour. Additionally, less than 2 cm spatial resolution at 10-ft measurement range was achieved with the prototype using only 6-mW laser power. In Phase II, POC plans to develop a shipboard-deployable SMILA prototype using a 1-W laser, enabling SMILA to concurrently measure three-component airflow velocities throughout a volume of interest (400 ft x 160 ft x 40 ft) with spatial and frequency resolutions of 2 ft and 20 Hz, respectively. The prototype developed in Phase II will be installed and tested in a Navy ship or similar platform recommended by the Navy.

Benefit:
Both the military and civilian sectors will benefit from the successful development of the SMILA system. Defense agencies will have a highly reliable, small, electromagnetic-interference-free optical technology to accurately profile airflow fields in the vicinity of full-scale rotorcraft operating near a ships deck. Velocity data from SMILA will help to both conduct a full-scale study of the aerodynamics of shipboard rotorcraft operations and successfully implement shipboard aircraft advanced vertical lift operations. Commercial applications of SMILA include wind flow monitoring near civil structures, other buildings, and wind turbines and analysis of rotor downwash on personnel and parked aircraft at airports and building helipads. SMILA can also be used to provide real-time wind velocity information for guided projectiles to autonomously correct their trajectories.

Keywords:
Rotorcraft, LADAR, velocity, Downwash, Shipboard, Self-Mixing, flow field, Airwake