Improved Opto-Coupler Design With Enhanced Performance

Novel Opto-Coupler design that delivers increased Current Transfer Ratio, high Reverse Breakdown Voltage and high Isolation Potential.


Optical couplers are an essential component in optical fiber circuits and other systems. They enable the splitting or combination of data transmitted as light waves instead of electrical signals. Optical couplers are also called opto-isolators, opto-couplers, photo-coupler, or optical isolator. An opto-coupler provides an isolated link between two potentially different circuits. They allow for a controlling entity to communicate through excitations of photons that rapidly change the conductance, which in turn prediabetes the current on the receiving side.. This isolation between circuits allows for various sensors/mechanisms to work within their operating parameters preventing damage to components and reduces crosstalk/noise that may otherwise cause interference with the individual circuits.

Competitive Advantage

The key advantage offered by this novel design is an overall improvement in the operating characteristics of opto-couplers targeted for space applications. Gradual loss of optical and mechanical properties is preventedby packaging the device in preferred space-qualified material. The housing is specifically designed and coated to allow enhanced light reflection from the LED while ensuring that the LED and the photodetector are not in contact with each other. Several process steps have also been altered or enhanced in this design to allow for better encapsulation of the components of the opto-coupler without affecting performance or size. This includes using novel materials and applying them in ways to improve overall product capability, specifically in terms of reliability, electric high-voltage isolation between the input and output terminals, and a high current transfer ratio.


Inventors at UNH have developed several novel aspects incorporated into a next generation opto-coupler design. By using more Light Emitting Diodes (LED) in the design, the Current Transfer Ratio (CTR) has been increased by a factor of 10 or better. These LEDs can be arranged in series or parallel configuration based on the application under consideration. The new LED package design demonstrates better thermal qualities such as reduced thermal resistance and controlled thermal effect by means of a thermal sink junction. The LEDs are closer in proximity to the high-voltage diode through the use of glass to encase the LEDs, a well-defined machining process, and lenses that have been machined to provide a thinner flat lens profile. This closer proximity allows for a higher CTR while maintaining desired standoff voltage compliance. Other design aspects, such as the material and unique square-shaped of the housing, help improve aspects such as electric field canceling function and controlled electron creepage distances in all directions. The overall design approach focused on reducing the number of parts to reducing overall cost and other quality assurance requirements for specific applications such as space equipment.

Market Oppourtunity

This opto-coupler design is specifically built for space-based applications. The novel features of this opto-coupler can also make it usable in computing and communication systems. Photocopiers, industrial automation, professional light measurement instruments and auto-exposure meters are also areas where rugged, high performance opto-coupler design of this type could find application.

Key Features

  • Utilization of more LEDs to increase Current Transfer Ratio by a factor of 10 or better
  • Better thermal management capability through reduced thermal resistance and thermal sink junctions
  • Compact design allows for closer proximity between the LEDs and the HV diode
  • Process steps that allow for higher performance and reduced number of parts to be designed and machined


  • Space
  • Optics
  • Computing
  • Communication

Intellectual Property Status

Patent pending

Stage of Development

Prototypes have been designed, produced, and tested

Lead Innovator

Brian King


Contact Information

Maithili Shroff, Licensing Manager, UNHInnovation