The red laser is a great friend of the film buff. It has been the key ingredient for extracting the data from billions and billions of DVDs, and thanks to increases in output power, it promises to now enable the manufacture of brighter, more colourful displays, including three-dimensional ones employed in cinemas, says Modulight’s Marketing Manager Anca Guina.

 

For more than a decade the red laser diode’s only high-volume application has been optical storage – the playback and recording of DVDs, which can store films and other forms of digital data. According to the US market research firm Strategies Unlimited, shipments of 300 million laser chips serving this application, which emit milliWatt outputs at 650 nm in pulsed mode, accounted for 98 percent of the $1.41 billion visible red laser market in 2008.

However, while this market will continue to be a very valuable one for red laser manufacturers for many years to come, any chipmaker looking to grow their revenues will need to start serving new applications too, because sales of 650 nm diodes for optical storage have saturated. What’s more, these laser makers will also have to look beyond the other well-established, but far smaller markets for low-power red lasers, including those for bar code scanners and industrial applications that employ these diodes for pointing and measurement.

At Modulight – a well-established Finnish in-house manufacturer of red diode lasers that has a technology that originates from Tampere University of Technology – we have been identifying alternative markets for red lasers. They require sources with higher output powers, typically 1W or more.

Our company, along with other makers of red lasers, expects these sources to play a growing role in the medical laser market, which had a value last year of $432 million, equating to just less than 7 percent of the entire laser market, according to Strategies Unlimited. In this sector, high power lasers can be used for therapy and illumination applications. However, producing lasers with higher output powers that can operate reliably for the length of time demanded by this application is challenging, and the lack of ‘killer applications’ in this sector discourages chipmakers from running expensive development programmes.

A more promising application for red lasers is the entertainment and display market. Although it was only valued at $32 million in 2010, it is forecasted to grow at an annual rate of 20 percent over coming years. The main attraction of turning to visible lasers, or LEDs for that matter, is that they promise to deliver a far wider colour space than that which is attainable with conventional lamp-based technology. By mixing the output of red, green and blue lasers, it is possible to produce significantly deeper colours while setting a new benchmark for brightness.

 



Increasing the output power of red, green and blue lasers from hundred of milliwatts to tens of watts enables colour projection systems to increase the image of the display

Products that could soon sport small versions of these projectors – known as a picoprojectors – are top-of-the- range mobile phones and digital cameras. This add-on will allow the user to project images, typically the size of this magazine, onto flat, light-coloured surfaces. The output power demands for this particular application are not that challenging, typically requiring between 200 and 400 mW, which is comparable to the power used to burn information onto a DVD.

Many companies with existing red laser technology for optical storage will be looking to enter the market for picoprojector lasers, which require low-power, singlemode sources. We, however, are more excited by the larger scale projection applications that require watt level multimode lasers, sources that only a handful of laser companies are capable of producing.

Getting lasers into TV…

A major breakthrough in this market has been thelaunch the first laser-TV by Mitsubishi in early 2008.Widespread adoption of this class of TV has beenhampered by its high price tag – although it has fallensince the launch of this product, a whopping 75-inchdisplay based on this technology still retails for $3500.

Consumers are also enjoying the benefits of severe price erosion in the high-quality end of the large size LCD TV market, and now take it for granted that they can have a screen thickness of just a few centimetres.

This may deter some home cinema lovers from investing in bulky, laser projection TVs that have a thickness of up to 30 cm.

One possible scenario is that laser diodes will find greater deployment in TVs, although not in the way pioneered by Mitsubishi. Instead, they could be used as backlighting for LCD displays, replacing the LED backlit technology that is starting to dominate this market now. Switching to laser-backlit LCD-TV could improve the colour gamut of these displays, and also usher in the ultimate power-lean, ‘green’ LCD-TV technology.

Another market where lasers are starting to be adopted is that of business projectors. Companies such as Casio have released products on this market that combine the emission of a blue laser with a red LED and a green source involving a diode-pumped phosphor. This market, which requires sources with outputs of several Watts, is dominated by consumer-related products. If laser makers are to enjoy commercial success in this arena, they have to produce low-cost lasers with a very high level of performance.

... and onto the big screen

Some of the most impressive projection systems arefound in movie theatres, which number more than115,000 around the globe. These theatres are movingtowards new projection technologies that are digital,and in some cases capable of generating threedimensionalimages. It will not be long before cinemasalso start turning to laser-based projection displays thatdeliver incredibly bright images with wonderfully realistichues and tones.

The inferiority of the incumbent lighting technology in cinema projectors, the Xenon lamp, is not restricted to colour temperature. It also has a very low efficiency, making it incredibly power hungry, and it is has to be replaced every 400-500 hours.

These weaknesses have encouraged projector manufacturers to investigate different lighting technologies using prototype laser sources. In September 2010 Kodak demonstrated a laser-based cinema projector. The Film Distributor’s Association has approved this for use in the US. Kodak has decided that it will not manufacture this product in-house, and is planning to license its technology to interested parties. Meanwhile, the Chinese firm Beijing Phoebus Vision has announced that it has developed laser-based cinema projection systems for domestic use. This company showcased a laser projector demonstrator during the opening ceremony of the Beijing Olympics.

Depending on the size of the screen, lasers used for cinema projection must produce between 50 W and 200 W of total power for each colour. Such a high output power is challenging to deliver from a reliable source. That’s because it is much more difficult to  manufacture visible lasers than their infrared cousins that have a far higher wall plug efficiency and are used in industrial applications.

However, the good news is that in cinemas, lasers are deployed in a controlled environment and do not require a wide operating temperature range and a demanding consumer product design. Instead, these systems can be built in an industrial manner. Currently, key players in cinema projection are planning strategies for this market and designing prototypes.

Tapping into the emerging markets

We believe that we are well placed to make inroads intothe emerging market for laser-based displays, and wehave already gained traction in the more establishedmarket for medical lasers. Our product portfolio spanslaser die to turnkey systems, which are all part of theSparklight product platform. We have also had successwith our ChiliLase red laser diode family, a range thatgoes from 500 mW single-emitter chips to 12 W fibercoupledlaser modules and systems. These productsthat were launched in 2007 have already won adoptionin medical and industrial applications, including ‘designins’to major OEMs such as PerkinElmer.

 

The Chililase standard product offerigng at Modulight ranges from 500 mW chips to 12 W fiber coupled laser modules and systems

In the last few years, our ChiliLase products have attracted the attention of the display market, which places a very high value on reliable, high-power visible lasers. In late 2009 we started supplying 500 mW, 635 nm lasers to Asia for deployment in displays, and last year we shipped more than 5000 Watts of ChiliLase products for this application.

The rapid adoption of these lasers has spurred us to further invest in the development of red lasers for displays. We are particularly keen to target multiWatt (>50 W per color) visible lasers for digital cinema projectors. Such laser systems at visible wavelengths are not commercially available, and we aim to change this, eventually bringing complete laser engines to this market that are based on our Sparklight laser system platform.

We anticipate that the business opportunity for red laser diode manufacture in cinema projectors will be at least $50-100 million over the next five-to-seven years. Additional sales for red lasers emitting 1 W or more will come from laser-TV and business-scale projectors and laser shows. Thanks to our in-house chip technology and system integration capability, we believe that we are in an excellent position to capitalize on this opportunity in the coming years. In fact, it would be fair to say that we see our future shining bright in the red dawn of the era of new display applications.

 

Modulight produces its red lasers in-house

 



Modulight’s fab in Tampere, Finland

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