Haitz's Law is an observation/prediction about the steady improvement over the years of light-emitting diodes – LEDs.

It states that every decade, the cost per lumen (unit of useful light emitted) falls by a factor of 10, the amount of light generated per LED package increases by a factor of 20, for a given wavelength (color) of light. It is considered the LED counterpart to Moore's Law

Moore's Law

Moore's law describes a long-term trend in the history of computing hardware: the number of transistors that can be placed inexpensively on an integrated circuit doubles approximately every two years....

, which states that the number of transistors in a given integrated circuit doubles every 18 to 24 months. Both laws rely on the process optimization

Process optimization

Process optimization is the discipline of adjusting a process so as to optimize some specified set of parameters without violating some constraint. The most common goals are minimizing cost, maximizing throughput, and/or efficiency...

 of the production of semiconductor devices. There is an important difference between the two laws: There is practically unlimited need for computing power so that the transistor count per integrated circuit will continue to rise until the physical limits are reached. On the other hand certain lumen-packages are well-suited for certain applications (~1 klm for residential lighting, ~10 klm for commercial lighting) and these lumen packages can be addressed already with today's technology. In principle it will be possible to go beyond these lumen packages in the years ahead, but this will be constrained to special applications and will have only limited commercial relevance in contrast to integrated circuit technology where there is always market demand for higher computing power.

Haitz's Law is named after Dr. Roland Haitz, a now-retired scientist at Agilent Technologies. It was first presented to the larger public at Strategies in Light 2000, the first of a series of annual conferences organized by Strategies Unlimited.

Besides the prediction of exponential development of cost per lumen and amount of light per package the publication also predicted that the efficiency of LED-based lighting could reach 200 lm/W (lumen

Lumen (unit)

The lumen is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux...

per Watt) in 2020 crossing 100 lm/W in 2010. This would be the case if enough industrial and government resources were spent for research on LED-lighting. More than 50% of the electricity consumption for lighting (20% of the totally consumed electrical energy) would be saved reaching 200 lm/W. This prospect and other stepping-stone applications of LEDs (e.g. mobile phone flash and LCD-backlighting) led to a massive investment in LED-research so that the LED efficiency did indeed cross 100 lm/W in 2010. Continuing the trend, LEDs will become the most efficient light source within the next 10 years.

In 2010, Cree, Inc, developed and marketed the XM-L LED that claimed 1000 lumens at 100/W efficiency and 160 lm/W @ 350mA and 150 lm/W @ 700mA. They also claimed to have broken the 200 lm/W barrier in R&D with a prototype producing 208 lm @ 350mA. In May 2011, Cree announced another prototype with 231 lm/W efficiency @ 350mA.