Burst PD being better than PD Laser isn't necessarily a reason to buff the PD Laser (power creep, anyone?) but what could get looked at are the breakpoints of killing a missile.
Let's use a Harpoon as a "typical" missile. It has 150 HP and is slow-ish. A Mining Laser would need 5 seconds to kill it and a PD Laser needs 2, if we talk base stats. There's no way the Mining Laser has 5 seconds on target, even it has an extra 150 range. However, 2 seconds on target for the PD laser is still probably too long. LRPD needs 3 seconds and with 800 range might actually be the sweet spot, though there's no guarantee it has its full range to work with if the enemy ship is closer than that. Burst PD does 128 damage per burst, so it takes two bursts to kill one (very nearly only needing one) but generally speaking, it will get the job done. At base values, one could argue that the PD laser is potentially needs a little range or a little more DPS to be worthwhile, especially since it costs 4 DP vs. the Mining Laser's 1. However, a single Mining Laser isn't ever going to stop a Harpoon. The PD Laser and LRPD might. The Burst PD will, if it has 2 charges.
Thing is, adding extra damage to missiles is laughably easy with either skills or hullmods. The Point Defense skill is going to add 50% more damage, as will IPDAI. S-modded Advanced Turret Gyros adds 25%. Just having 100% CR adds 10% damage and Energy Weapon Mastery will add some small-to-moderate +damage to the beams. All this to say that Energy PD is rarely at base values. If a ship has the PD skill or IPDAI, now a PD laser only needs 1.33 seconds to kill the harpoon and the LRPD only needs 2. Burst Lasers shoot the Harpoon down in 1 shot. Yet, the Mining Laser still needs 3.3 seconds, still probably too long but for 1 OP, what do you expect?
You can't just bump up DPS, in general, either. LRPD already encroaches on the Tac Laser and the PD Laser has the same 75 DPS at half the flux cost. Bonuses to missiles/fighters would be the way I'd go about it. Personally, I'd adjust the Small Energy PD lineup to something closer to this:
Mining Laser - leave as-is. No bonuses to missiles/fighters but base DPS feels pseudo-competitive for the cost.
PD Laser - reduce to 50 base DPS, +100% to missiles/fighters (33% increase vs missiles over current but 50% worse as a general-purpose weapon)
LRPD - reduce to 25 DPS, +100% to missiles/fighters (same as current but is 1/3rd as effective as the Tac Laser in the same role)
Tac Laser - leave as-is. By far the most general-purpose now.
Burst PD - leave as-is.
Skill/hullmod bonuses multiply the base DPS before the inherent bonuses, bringing them to current levels. For example, PD Laser with PD skill would have a (50*1.5) * 2 = 150 which is the same as current against missiles but only 75 DPS against hull/shields. All-in-all, Energy PD would be more specialized, the PD Laser receives a moderate buff as an actual PD platform, the Tac Laser is more attractive by proxy and Burst PD remains the Elite go-to if you have the OP to spare.