Solid State Lighting with Blue Laser Diodes Robert Gatdula, Jared Murray, Avery Heizler, Meet Shah

supervised by Prof. Wei Jiang

LED bulbs have already gone to the mass-market and have

proven to be more efficient and affordable compared to

incandescent and fluorescent lighting. However, next-

generation lighting may truly dominate from a different

type of solid-state device -- the laser. Laser-based lighting

has the potential to be more efficient given the right safety

measures and proper circuitry.

Luxury car manufacturer BMW has already developed a

headlight prototype proving this technology in their i8

concept car, and Laser Phosphor-based Displays (LPDs)

have already been developed by Prysm, Inc for large display

platforms.

Our project focuses on the theory behind this type of

lighting as well as explains why it should shine over LED

technology.

ABSTRACT/INTRODUCTION: ______ STOKES SHIFT AND WHITE LIGHT GENERATION: ______

Blue light hits yellow phosphor

Yellow phosphor emits yellow light (Stokes Shift )

Unabsorbed blue light with yellow light give white

light

LED/LASER DIODE DRIVER: ______

Buck converter with a

current sense feedback

Free running oscillation

High side N-Fet with

Bootstrap gating

Adjustable load current

166kHz switching

frequency

Soft turn-on of LED

CIE 1931 COLOR SPACE & COLOR TEMPERATURE: _____

The image above is the light produced by a blue LED coated with yellow phosphor.

Data points on the CIE 1931 color space show that the color is around white with a color temperature somewhere

between 6000 and 10000. LUMINOUS EMITTANCE: ______

LASER-BASED vs. CONVENTIONAL LIGHTING: ______

Laser diodes have better stability at higher current than LEDs -- allows for

high power applications.

The intensity of light in lased diodes is higher than that of LEDs at

comparable power levels.

Laser diodes have a longer illumination distance

Image on the right shows laser-based lighting (left) compared to

incandescent lighting (right)

Phosphor coating

Blue Laser Diode

Reflected light

Beam scattering at the surface of the phosphor

White light (blue and yellow beams used for illustrative purposes)

0 0.2 0.4 0.6 0.8 1

0

0.2

0.4

0.6

0.8

1

t1

t2

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

0 5 10 15 20 25

Lum

ino

us

Emit

tan

ce (

lux)

Current (mA)

Lux vs. Current (13 cm away from source)

Mirror 1

Mirror 2

Mirror 3

Mirror 4

Lens 1

0.0

20.0

40.0

60.0

80.0

100.0

120.0

0 5 10 15 20 25 30 35 40 45

Lum

ino

us

Emit

tan

ce (

lux)

Distance (cm)

Lux vs. Distance (V = 3.58 V, I = 8.54 mA)

0.0

20.0

40.0

60.0

80.0

100.0

120.0

0 5 10 15 20 25 30 35 40 45

Lum

ino

us

Emit

tan

ce (

lux)

Distance (cm)

Mirror vs. Lens

Mirror 4

Lens 1